A is an expression obtained through an iterative process of representing a number as the sum of its integer part and the reciprocal of another number.

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7
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2answers
356 views

Continued fractions

I'd really love with concluding that for given integers $a_0,a_1,...a_N$ with $a_i>0$ for $i>0$, representing the continued fraction $[a_0; a_1,....,a_N]$, with the following recursion: ...
1
vote
1answer
39 views

Definite integral of a continued fraction function

I came up with this function written as the following continued fraction (please correct me if my notation is incorrect): for $n\in\mathbb{N}$, let $$f(x;n)=x+\operatorname*{\LARGE ...
1
vote
0answers
19 views

Stern-Brocot Tree and sum of coefficients of continued fraction

Suppose we are given a continued fraction $$\frac{p}{q}=a_{1}+\frac{1}{a_{2}+\frac{1}{a_{3}+\frac{1}{a_{4}+\cdots}}}$$ I am trying to find an expression, possibly asymptotic, for the sum of the ...
1
vote
0answers
27 views

Recommended reading for continued fractions? And some results

First of all, I apologize for my amateurness and inexperience. Although I always enjoyed math, only two years ago I started experimenting with continued fractions and gained a deep reverence for them. ...
2
votes
5answers
81 views

Limit of the sequence defined by a recurrence

Given a recurrence formula for an arithmetic sequence, $$U_{n} = \frac{1}{2+U_{n-1}}$$ Show that$$\frac{1}{2+\frac{1}{2+\frac{1}{2+\frac{1}{2+ ...}}}} = (SomeGivenValue)$$ How can we solve questions ...
25
votes
1answer
978 views

A continued fraction involving prime numbers

What is the limit of the continued fraction $$\cfrac{1}{2+\cfrac{1}{3+\cfrac{1}{5+\cfrac{1}{7+\cfrac{1}{11+\cfrac{1}{13+\cdots}}}}}}\ ?$$ Is the limit algebraic, or expressible in terms of e or ...
1
vote
0answers
77 views

Continued fraction and order of a real number

If $\alpha$ is a irrational number prove that $\operatorname{ord}\alpha \geq 1+\exp(\limsup \log(\log(a_n+1))/n)$ I tried the simple things like use the well known formula $\operatorname {ord}\alpha ...
4
votes
0answers
53 views

The $q$-continued fraction for tribonacci constant and others

Let $q = e^{-2\pi}$. We are familiar with Ramanujan's beautiful continued fraction, $$\cfrac{q^{1/5}}{1 + \cfrac{q} {1 + \cfrac{q^2} {1 + \cfrac{q^3} {1+\ddots}}}} = {\sqrt{5+\sqrt{5}\over ...
1
vote
0answers
14 views

Continued fraction expansion of $1-x$ for $x\in [0,1[$.

If $\alpha$ is a real number in $[0,1[$ that can be written as $[a_0;a_1,a_2,\ldots]$, what can I say about the continued fraction expansion of $1-\alpha$?
3
votes
0answers
28 views

How to write this function in a “well-formed” way

Given an input $0 \lt x \lt 1$, find $x$'s Nearest Integer Continued Fraction with structure $$x = a_0 \pm \cfrac{1}{a_1 \pm \cfrac{1}{a_2 \pm \cdots}}.$$ Then $$f(c) = a_0 + 1 \mp \cfrac{1}{a_1 + ...
0
votes
2answers
27 views

Sum and Product of continued fraction expansion?

Give the continued fraction expansion of two real numbers $a,b \in \mathbb R$, is there an "easy" way to get the continued fraction expansion of $a+b$ or $a\cdot b$? If $a,b$ are rational it is easy ...
57
votes
3answers
667 views

Closed form solution for $\sum_{n=1}^\infty\frac{1}{1+\frac{n^2}{1+\frac{1}{\stackrel{\ddots}{1+\frac{1}{1+n^2}}}}}$.

Let $$ \text{S}_k = \sum_{n=1}^\infty\cfrac{1}{1+\cfrac{n^2}{1+\cfrac{1}{\ddots1+\cfrac{1}{1+n^2}}}},\quad\text{$k$ rows in the continued fraction} $$ So for example, the terms of the sum $\text{S}_6$ ...
7
votes
4answers
194 views

how to solve $3 - \cfrac{2}{3 - \cfrac {2}{3 - \cfrac {2}{3 - \cfrac {2}{…}}}}$

$$A = 3 - \cfrac{2}{3 - \cfrac {2}{3 - \cfrac {2}{3 - \cfrac {2}{...}}}}$$ My answer is: $$\begin{align} &A = 3 - \frac {2}{A}\\ \implies &\frac {A^2-3A+2}{A}=0\\ \implies &A^2-3A+2=0\\ ...
6
votes
2answers
66 views

Specification of Hurwitz's Theorem

Hurwitz's Theorem in Number Theory states that for every irrational number $\xi$, the equation $$\left|\xi-\frac{p}{q}\right|<\frac{1}{\sqrt{5}q^2}$$ has infinitely many solutions $(p,q)$ ...
0
votes
1answer
57 views

determine the continued fraction of $\sqrt{n^2 + 2}$ for $n \in \mathbb{N}$

determine the continued fraction of $\sqrt{n^2 + 2}$ for $n \in \mathbb{N}$. For rationals it is rather easy to do this and i know the algorithm, i only get stuck a lot by irrational number such as ...
2
votes
1answer
59 views

Which continued fraction for $e$ is the most computationally efficient?

I know that famous numbers like $\pi$ and $e$ have multiple representations as continued fractions and I'm fascinated with the variety of representations. My question: What continued fraction for ...
1
vote
0answers
19 views

Convergents of continued fractions

Let $d$ and $m$ be positive integers such that $d$ is not a square and such that $m\leq\sqrt{d}$. I want to prove that if $x$ and $y$ are positive integers stafisfying $x^2-dy^2=m$ then $x/y$ is a ...
7
votes
2answers
695 views

Baire space homeomorphic to irrationals

I try to show that the Baire space $\Bbb N^{\Bbb N}$, with regular product metric, is homeomorphic to the unit interval of irrationals $(0,1)\setminus\Bbb Q$. I already know that the needed function ...
1
vote
1answer
25 views

How to calculate remainder value of a fraction

Question: Four brothers split a sum of money between them. The first brother received 50% of the total, the second received 25% of the total, the third received 20% of the total, and the fourth ...
-1
votes
1answer
57 views

Find the real number $x$ represented by continued fraction $[12;2,2,12,2,2,12,2,2,12\dots]$

I need to fins the real vlaue of x for the continued fraction (Image attached) I have tried partial coefficient method, but didn't get the exact answer. I there any way where we can identify the ...
-1
votes
5answers
54 views

Find $x$ defined as a continued fraction [duplicate]

I have solved the above using the below method. $$x= 12 + \frac{1}{2+\left(\frac{1}{2}+x\right)}$$ After solving for $x$, I got the answer as $11.7515$ and $-1.41824$ So what is the real value of ...
2
votes
1answer
31 views

Find the sum of the integers in the continued fraction

Find the sum of integers $a,b,c,d,$ and $e$ if $\dfrac{2011}{1990} = a+\dfrac{1}{b+\dfrac{1}{c+\dfrac{1}{d+\dfrac{1}{e}}}}$. I could simplify the big fraction on the RHS, but I don't see how that ...
-1
votes
0answers
123 views

Calculate the closed form of an infinite continued fraction

Is there a way to algebraically determine the closed form of this infinite continued fraction of the form : (clic here please) $$ F_n=\frac{1}{-i\omega+ A \frac{ (n+1)^2}{4(n+1)^2-1}F_{n+1}} $$ $A$ ...
2
votes
0answers
44 views

Rogers-Ramanujan continued fraction $R(e^{-2 \pi \sqrt 5})$

Let $$R(q) = \cfrac{q^{1/5}}{1 + \cfrac{q}{1 + \cfrac{q^{2}}{1 + \cfrac{q^{3}}{1 + \cdots}}}}$$ It is easy to evaluate $R(e^{-2 \pi/ \sqrt 5})$ using the Dedekind eta function identity ...
0
votes
0answers
53 views

integrating continued fractions

How do you integrate: $$\int \underset{j=1}{\overset{\infty}{\LARGE\mathrm K}}\frac{a_jx^j}{b_j}dx=\int x\cfrac{a_1}{b_1+\cfrac{a_2x}{b_2+\cfrac{a_3x^2}{b_3+\ddots}}}dx$$ Can you use closed form?
1
vote
1answer
21 views

Evaluating a continued fraction

I have a continued fraction in List form: $[0;1,2,1,2...]$ (the $1,2$ are repeated). Evaluating this should give $-1 + \sqrt3$. I am not sure how to get that answer. I am aware of to express ...
21
votes
0answers
359 views

Curious about an empirically found continued fraction for tanh

First of all, and since this is my first question in this forum, I would like to specify that I am not a professional mathematician (but a philosophy teacher); I apologize by advance if something is ...
1
vote
1answer
52 views

a conjecture of two equivalent q-continued fractions related to the reciprocal of the Göllnitz-Gordon continued fraction A111374-OEIS

Given the square of the nome $q=e^{2i\pi\tau}$ and ramanujan theta function $f(a,b)=\sum_{k=-\infty}^{\infty}a^{k(k+1)/2}b^{k(k-1)/2}$ with $|q|\lt1$, define, ...
3
votes
0answers
105 views

Asymptotic solutions of a sparsely perturbed recurrence relation

Recurrence relation I am trying to find approximate solutions $T(n)$ of the recurrence relation $$ p\ T(n-1) - \left[p+q+\overline{S} + \varepsilon \tilde{S}(n)\right]T(n) + q\ T(n+1) = 0,\\ ...
1
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0answers
25 views

Textbooks on transcendence theory

Is there a nice, modern textbook (some lecture notes or survey would do, too) that covers the main results and methods from transcendence theory? Ideally, it should also have some good exercises. So ...
0
votes
1answer
45 views

How to find cases where $m^2$ is near to $2^A$?

In another problem here in MSE I ran into the question how I can (practically, in a program) find (positive) integer $m$ such that they are "near" to perfect powers of $2$, so $$ (0 \lt ) \qquad d_m ...
4
votes
2answers
130 views

Upward continued fractions

Has anybody seen "upward continued fractions", such as $$ \frac{1+\large{\frac{1+\large{\frac{1+...}{a_2}}}{a_1}}}{a_0} \quad? $$ These can be formed, for any real number $x$ with $0<x\le 1$, by ...
9
votes
1answer
333 views

a conjectured continued-fraction for $\cot\left(\frac{z\pi}{4z+2n}\right)$ that leads to a new limit for $\pi$

In this post,I posed a similar conjecture for $\displaystyle\tan\left(\frac{z\pi}{4z+2n}\right)$ but did not get any helpful answers. Given a complex number ...
8
votes
0answers
310 views

a conjectured continued fraction for $\displaystyle\tan\left(\frac{z\pi}{4z+2n}\right)$

Given a complex number $\begin{aligned}\frac{z}{n}=x+iy\end{aligned}$ and a gamma function $\Gamma(z)$ with $x\gt0$, it is conjectured that the following continued fraction for ...
4
votes
1answer
119 views

Continued Fraction: Please prove $\frac{1}{e \gamma (x+1,1)}=x+\frac{1}{x+1+\frac{2}{x+2+\frac{3}{x+3+\frac{4}{\dots}}}}$

I have been playing around with Mathematica and continued fractions and I noticed something. ContinuedFractionK[n, n + x, {n, 1, Infinity}] ==-x + 1/(E Gamma[1 + x] - E Gamma[1 + x, 1])==-x + 1/(E ...
5
votes
1answer
113 views

Rogers-Ramanujan continued fraction in terms of theta functions?

The Rogers-Ramanujan cfrac is, $$r = r(\tau)= \cfrac{q^{1/5}}{1+\cfrac{q}{1+\cfrac{q^2}{1+\ddots}}}$$ If $q = \exp(2\pi i \tau)$, then it is known that, $$\frac{1}{r}-r ...
5
votes
1answer
67 views

Two similar integration about continued fractions

Prove that \begin{align*} \int_0^{+\infty} \cfrac{\sin nx}{x + \cfrac{1}{x + \cfrac{2}{x + \cfrac{3}{x + \cdots}}}} \, dx &= \cfrac{\sqrt {\cfrac{\pi }{2}} }{n + \cfrac{1}{n + \cfrac{2}{n + ...
0
votes
2answers
39 views

Are the numerator and the denominator of a convergent of a continued fraction always coprime?

Is it true that for a convergent $A_k = p_k/q_k$ of the continued fraction expansion $[a_0;a_1,a_2,\dots]$ the numerator $p_k$ and the denominator $q_k$ are always coprime? If yes, how would one show ...
20
votes
2answers
528 views

Evaluation of a continued fraction

Puzzle question... I know how to solve it, and will post my solution if needed; but those who wish may participate in the spirit of coming up with elegant solutions rather than trying to teach me how ...
0
votes
0answers
41 views

Prove that $p_nq_{n-1}$ - $p_{n-1}q_n=(-1)^{n-1}$ for $p_{-2}=0$ $p_{-1}=1$ $q_{-2}=1$ $q_{-1}=0$

Let $p_n$/$q_n$ for $n=0,1,2,..$ be the convergents of $a∈ R$ $p_{-2}=0$ $p_{-1}=1$ $q_{-2}=1$ $q_{-1}=0$ $p_n= a_np_{n-1}+p_{n-2}$ $q_n= a_nq_{n-1}+q_{n-2}$ I need to prove that $p_nq_{n-1} - ...
2
votes
1answer
45 views

Square root of continued fraction

Assuming I've been given a number in the form of a continued fraction. Is there a general way to write the square root of that number as continued question? For example, consider $$1+\sqrt{2} = ...
5
votes
4answers
154 views

Find the continued fraction of the square root of a given integer [duplicate]

How to find the continued fraction of $\sqrt{n}$, for an integer $n$? I saw a site where they explained it, but it required a calculator. Is it possible to do it without a calculator?
0
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0answers
13 views

Q-D scheme, continued fractions

What is a Q-D scheme for a continued fraction? I am reading this text on numerical evaluation of the H-function and the author suggests using continued fractions as done by many other special ...
15
votes
1answer
317 views

Nested solutions of a quadratic equation.

A quadratic equation of the form $x^2+bx+c=0$ can be solved with the classical formula that gives all solutions. Here I want discuss some other methods to find one solution. The best known is by ...
7
votes
2answers
248 views
1
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1answer
35 views

Convert partial fraction to continued fraction?

Lets say you have a partial fraction of the form: $$ f(x) = a_0 + \sum_{n=0}^{\infty} \frac{a_n}{\lambda_n + x} $$ Can anyone explain to me, in mildly plain English, how to convert this partial ...
0
votes
1answer
20 views

Show simple continued fraction with Euclid's Algorithm

I have this math problem, I have to show a simple continued fraction from equations. Here's the question. Use these equations: $$397 = 204(1) + 193$$$$204 = 193(1) + 11$$$$193 = 11(17) + 6$$$$11 ...
5
votes
2answers
166 views

A $q$-continued fraction connected to the divisor function?

In this post, the following two continued fractions discussed by Nicco are given, $$A(q)= \left(\frac{\vartheta_2(0,q)}{2\,q^{1/4}}\right)^2= ...
5
votes
1answer
67 views

Where to learn about continued fractions?

I sought a convergent subsequence of $\sin n$, and I met a proof that utilizes continued fractions. I always stumble upon things related to them as well. So, I would like to learn about them. What is ...
4
votes
2answers
290 views

Ramanujan theta function and its continued fraction

I believe Ramanujan would have loved this kind of identity. After deriving the identity, I wanted to share it with the mathematical community. If it's well known, please inform me and give me some ...