0
votes
1answer
44 views

Solving the recurrence relation $T(n)=4T\left(\frac{\sqrt{n}}{3}\right)+ \log^2n$

How we calculate the answer of following recurrence? $$T(n)=4T\left(\frac{\sqrt{n}}{3}\right)+ \log^2n.$$ Any nice solution would be highly appreciated. My solution is: $n=3^m \to ...
1
vote
1answer
33 views

Recurrence Relation - Merge Sort

We know the recurrence relation for normal merge sort. It is T(n) = 2T(n/2) + n. After solving it we can get T(n) = cnlogn. I ...
2
votes
0answers
32 views

Solving the recurrence $T(n)=4T(\frac{\sqrt{n}}{3})+ \log^2n$ [on hold]

How we calculate the answer of following recurrence? $$T(n)=4T\left(\frac{\sqrt{n}}{3}\right)+ \log^2n.$$ Any nice solution would be highly appreciated.
1
vote
0answers
72 views

Comment on this Pi Formula? [on hold]

I compute Pi in my own way as follows: $$\frac{\pi}{2}=1+\frac{1}{1+\frac{1}{\frac{1}{2}+\frac{1}{\frac{1}{3}+\frac{1}{\frac{1}{4}+\frac{1}{\vdots}}}}}$$ and use ...
1
vote
2answers
46 views

Solve $T(n) = T(n-1)+\log^2(n)$

I was trying to solve $T(n) = T(n-1)+\log^2(n)$ using substitution method and variables substitution but I can't find the correct answer. My attempt: Let $m = \log(n)$ then $T(2^m) = ...
4
votes
5answers
89 views

How to solve the recurrence relation $T(n) = T(\lceil n/2\rceil) + T(\lfloor n/2\rfloor) + 2$

I'm trying to solve a recurrence relation for the exact function (I need the exact number of comparisons for some algorithm). This is what i need to solve: $$\begin{aligned} T(1) &= 0 \\ T(2) ...
2
votes
1answer
57 views

Recurrence - using power series

Could you help me in solving this recursion( a closed form ) using power series $\mu(n)=\mu(n−1)k_0+(n−1)\mu(n−2) k_1 \tag 1$, where $k_0,k_1$ are constants $\mu(0)=3,\mu(1)=5$ HINT: We can think ...
0
votes
1answer
23 views

Summation of infinte series

Sir, I have three infinite summation $A =J_1 \sum_{n=2}^\infty (n-1) f(n-2) \tag 1$ , $B =\sum_{n=0}^\infty f(n) \tag 2$ and $C =J_2\sum_{n=1}^\infty f(n-1) \tag 3$, with ...
1
vote
1answer
48 views

Infinite series for recurrence

Question 1 If I define $A(z) = \sum_{n \ge 0} a_n \frac{z^n}{n!} \tag 1$ (where $a_n$ are $3\times 3$ constant matrices indexed with n), then can we re-write $\sum_{n \ge 1} a_{n-1} \frac{z^n}{n!} ...
3
votes
2answers
89 views

Fibonaaci Recurrence

This is an interesting question where we are trying to solve another recursion which has same tree structure as the given recursion and also has term similarities Given Data in question ...
0
votes
0answers
23 views

Solving a simple Recurrence in summation form(very special case)

I have a bit confusing recursion form $\sum_{n=2}^{\infty}\{f(n)\frac{n}{n-1}\}=C, \tag 1$ $f(0)=b,f(1)= a,f(2)=c$ and $C$ are constants. Could you help me to solve this recursion or help me to ...
7
votes
3answers
219 views

Solving recurrence relation: Product form

Please help in finding the solution of this recursion. $$f(n)=\frac{f(n-1) \cdot f(n-2)}{n},$$ where $ f(1)=1$ and $f(2)=2$.
0
votes
0answers
17 views

Comparing Generalized Continued Fractions

Gosper lays out a method (under Approximations) for comparing regular (a.k.a simple) continued fractions which have all partial numerators set to 1. Continue comparing terms until they differ, then ...
0
votes
0answers
23 views

Produce a list of the most-similar units, given various correlations/relationships

I have a database full of units (U1 - U50, U51...) where every unit has the same standard attributes (A1 - A10) and where a % of each attribute defines the amount of that attribute for that particular ...
3
votes
1answer
74 views

Limit of a recursiv trigonometric function

So while doing my math homework I recently stumbled upon this little thing: It seems that $y_n = \sin(y_{n-1}) + k$ with arbitrary $y_0$ and $k$ converges to a definite value for $n \to \infty $. ...
1
vote
2answers
29 views

Finding the inhomogeneous solution

$x_{n+2} = x_{n+1} + 20x_n + n^2 + 5^n \text{ with } x_0 = 0 \text{ and } x_1 = 0$ How would I find the inhomogeneous solution for this since the homogenous solution is 0 given initial conditions?
1
vote
1answer
37 views
0
votes
2answers
36 views

Help solving recursive relations

$x_{n+2} = x_{n+1} + 20x_n + n^2 + 5^n \text{ with } x_0 = 0 \text{ and } x_1 = 0$ How would you solve this recursive relation? I have the homogenous solution, but am having issues with the ...
1
vote
1answer
25 views

recursive relation for putting signs in 2*n table

Consider we have a $2\times n$ table and we want to put a sign in some of the cells, and we don't put signs in both adjacent cells give a recursive phrase that shows that how many ways we can do that? ...
-2
votes
1answer
42 views

N balls of k colors on a cirlce, no two neighboring balls have same color - recursive algorithm

Suppose we have N balls of k different colors. What is the number of arrangements of these N balls on a circle with no two neighboring balls having the same color? Actually, the task is to make up a ...
0
votes
1answer
59 views

Recursive Function - $f(n)=f(an)+f(bn)+n$

I've got this recursive function $f(n)=f(an)+f(bn)+n$, and I need to find $θ$ on $f(n)$, as $a+b>1$. Using a recursive tree, I managed to bound it by $n\log(n)$ from the bottom and by $n^2$ from ...
-1
votes
1answer
45 views

How should I proceed to solve this recurrence relation: $T(n) = T(n - 1)^2$

I tried to solve this recurrence relation, but I was confused when I had to determine the pattern. $$ T(n) = \begin{cases} 3, & \text{if }n = 0 \\ T(n - 1)^2, & \text{if }n > 0 \end{cases} ...
1
vote
0answers
62 views

Solving a Recurrence Relation With Summation and Tau Function

How can I solve the following: $$ T(n) = \sum_{i = 1}^{d(n) - 2}T(v_i) + \sum_{i = d(n) - 1}^{n - 1}c + c' $$ Where $d(n)$ is the Tau function, and v is the set of values dividing n. e.g. $d(18) = ...
2
votes
0answers
26 views

Verify that this recurrence relation is in O(log n)

For the recurrence $T(n)=2*\lceil\frac{n+1}{2}\rceil+c$ is in $\Theta(lg n)$ My attempt at a solution (mostly just wanting to verify its correct). Lower Bound: $T(n)=2*\lceil\frac{n+1}{2}\rceil+c$ ...
1
vote
2answers
57 views

Solving this recurrence relation

Hi all I'm preparing for a midterm and the following appeared as a practice problem that I'm not quite sure how to solve. It asks to find a tight bound on the recurrence using induction $$ {\rm ...
0
votes
1answer
71 views

Quadratic Map Solution

I read this on Wolfram Alpha. It states that: a quadratic recurrence relation uses a second degree polynomial to express $x_{n+1}$ as a function of $x_n$. A "quadratic map", then, is a recurrence ...
0
votes
1answer
25 views

Recursive Algorithm Analysis

$$T(n) = 2\cdot \sqrt{n} \cdot T(\sqrt{n}) + \Theta (\lg n)$$ I have been trying to solve this question but I could not find anything. My approach: $n = 2^k$ $S(k) = T(2^n)$ and $S(k/2) = ...
1
vote
3answers
157 views

Recurrence relations (Big-O notation)

Say I'm given a recursive function such as: function(n) { if (n <= 1) return; int i; for(i = 0; i < n; i++) { function(0.8n) } } ...
0
votes
3answers
33 views

A closed form for the recursion?

Let $x$ and $y$ be real numbers and $x < y$ Given the recursion: $m_0 = \frac{x+y}{2}$ and $m_1 =\frac{m_0+ y}{2}$, so in general, $$m_i = \frac{m_{i-1} + y}{2}$$.. What is $m_{\infty}$? thanks ...
2
votes
1answer
75 views

Solve the recurrence relation:$T(n)=\sqrt{n}T\left(\sqrt{n}\right)+\sqrt{n}$ [closed]

I have doubt in solving the following questions: $T(n)=2T(\sqrt{n})+n$ $T(n)=\sqrt{n}T(\sqrt{n})+c$ $T(n)=\sqrt{n}T(\sqrt{n})+\sqrt{n}$ T(2)=1 for all the problems Atleast give the final answer.
4
votes
3answers
159 views

How does $\tbinom{4n}{2n}$ relate to $\tbinom{2n}{n}$?

I got this question in my mind when I was working on a solution to factorial recurrence and came up with this recurrence relation: $$(2n)!=\binom{2n}{n}(n!)^2$$ which made me wonder: is there also a ...
1
vote
1answer
95 views

Help with Recursive Algorithm

We are to determine a recurrence relation for a recursive algorithm. Let us use the Josephus Problem for this: Given n people standing in a circle, every kth person is killed until one person ...
1
vote
1answer
90 views

What's a useful recurrence relation for $(2n)!$ in terms of $n!$?

I want to make an algorithm for $n!$ which will divide the number in half and call the algorithm again until n is so close to $0$ that a value of $1$ can be safely returned, and use the value of each ...
1
vote
1answer
61 views

Creating Recurrence

If I have an integer $n \geq1$, and I had to draw $n$ straight lines, so that no two of them are parallel as well as no three of them intersect in one single point. These lines divide the plane into ...
1
vote
4answers
39 views

Identity for this recursive relation with multiple terms

I have a recursive relation algorithm which is defined as follows: $$F_n = 3(F_{n-1} - F_{n-2}) + F_{n-3}$$ $$F_0 = 0$$ $$F_1 = 1$$ $$F_2 = 4$$ From calculating the first few values, I know this is ...
2
votes
2answers
105 views

Internet problem solving contest question

I am trying to solve a problem from the IPSC http://ipsc.ksp.sk/2001/real/problems/f.html It basically asks to compute the following recursion. ...
0
votes
3answers
157 views

Difficult recursion problem

A student can do the things bellow: a. Do his homework in 2 days b. Write a poem in 2 days c. Go on a trip for 2 days d. Study for exams for 1 day e. Play pc games for 1 day A schedule of n days ...
0
votes
2answers
86 views

Repertoire Method. How to know when equations are valid

I'm trying to work a few examples from the Repertoire Method from the Book Concrete Mathematics. I'm working through the following recurrence: $f(0) = 1$ $f(n) = 2f(n-1) + n$ Which I generalized ...
0
votes
0answers
31 views

Understanding the difference between two similar looking recurrences.

Looking at this recurrence, $f(n) = f(n/2) + nlgn$ The book claims we can conclude that $f(n) = \Omega(nlgn)$ since $f(n/2)>0$. Furthermore, for a sufficiently large $n: lgn \le n^{\epsilon}$ for ...
0
votes
2answers
34 views

Number of ways to arrange n identical stones into piles

Given, there are n stones which are identical. How many ways can the stones be arranged into piles. Suppose if n=4 , we can make one pile with 4 stones or 2 piles with 3,1 or 2,2 or 3 piles with 1,1,2 ...
2
votes
1answer
88 views

number of derangements

In the normal derangement problem we have to count the number of derangement when each counter has just one correct house,what if some counters have shared houses. A derangement of n numbers is a ...
1
vote
0answers
45 views

How to derive recursive equation for expected discounted utility function?

I am trying to mathematically represent expected discounted utilities when the length of a lifetime is uncertain. $V_0$ is the expected discounted utility at $t=0$ and can be represented as such: ...
2
votes
4answers
116 views

find $O$ and $\Omega$ bounds as tight as possible for $T(n)=n+T(\frac n 2)+T(\frac n 4)+T(\frac n 8)+…+T(\frac n {2^k})$

find $O$ and $\Omega$ bounds as tight as possible for $T(n)=n+T(\frac n 2)+T(\frac n 4)+T(\frac n 8)+...+T(\frac n {2^k})$ while k is some constant and for any $n\leq3$ $\ T(n)=c$ for k=1 ...
1
vote
0answers
139 views

Help with find recurrence relation running time.

Write a recurrence relation describing the worst case running time of each of the following algorithms, and determine the asymptotic complexity of the function defined by the recurrence relation. ...
3
votes
2answers
146 views

Google Question: Number of ways to select sets such that n is pure

Consider a subset $S$ of positive integers. A number in $S$ is considered pure with respect to $S$ if, starting from it, you can continue taking its rank in $S$, and get a number that is also in $S$, ...
0
votes
1answer
116 views

Recurrence Relation for Optimal Card Game Score

I have the following problem where Alice and Bob decide to play a simple card game. At the beginning of the game, $n$ cards are dealt face up in a long row. Each card is worth a different number of ...
2
votes
1answer
63 views

Recurrence relation of an integral [closed]

$$ y_n = \int_0^1 \frac{x^n}{x+5} dx,\ \ n=0,1,2,...,\infty $$ What is the recurrence relation between $y_n, y_{n-1}$ ? Could you provide me a methodology on how to proceed with this?
1
vote
2answers
69 views

How does my textbook solve this summation equation for the answer?

Summations have always been my weakness in mathematics, and it's showing here as I'm very confused how my textbook, Introduction to Algorithms, goes from basically the second half of the following ...
2
votes
1answer
89 views

What is the bound of: $T(n) = T(n-2) + (n)log(n)$?

I am given the following recurrence relationship: $\ T(n) = T(n-2) + nlog(n)\\ T(1) = T(0) = constant$, I need to find the order for the recurrence. So, using the iterative methodology, what I ...
1
vote
1answer
54 views

How does my textbook come up with this statement? I don't believe it to be true.

My textbook (Introduction to Algorithms) states the following: When polynomially comparing $n^\epsilon$ and $lgn$, it states that $n^\epsilon$ is polynomially greater for any positive $\epsilon$. ...