CIJ
  • Member for 7 years, 5 months
  • Last seen more than 3 years ago
  • Mexico City, México
0 answers
9 votes
132 views
1 bookmarks
If $n^x\in\Bbb Z,$ for every $n\in\Bbb Z^+,$ then $x\in\Bbb Z$
4 answers
6 votes
328 views
2 bookmarks
Looking for a direct proof of the following exercise
3 answers
6 votes
122 views
If $f_{n-1}^2=(f_n/2)^2+h^2$ then $n=6$
3 answers
4 votes
108 views
The integer $n$ is not zero if and only if there is some prime $p>n$ such that $p-n$ is composite
3 answers
4 votes
678 views
Inequality of the Fibonacci sequence and the golden ratio
1 answers
4 votes
170 views
1 bookmarks
Find all functions $f:\Bbb Q\rightarrow\Bbb Q$ satisfying $f(x+y)+f(x-y)=2f(x)+2f(y)$ for all $x,y\in\Bbb Q$
0 answers
4 votes
112 views
If $x$ and $y$ are positive integers then $\frac{(2x)!(2y)!}{x!y!(x+y)!}$ is an integer
1 answers
3 votes
1k views
3 bookmarks
$\pi(x)\geqslant\frac{\log x}{2\log2}$ for all $x\geqslant2.$
0 answers
3 votes
421 views
1 bookmarks
Looking for an alternative solution for the mutilated chessboard problem
2 answers
2 votes
80 views
If $a_i>o$ then $(a_1a_2\cdots a_{2^n})^{1/2^n}\leq \frac{a_1+a_2+\cdots+a_{2^n}}{2^n}$
0 answers
1 votes
80 views
Piecewise defined funcion is Riemann-integrable
1 answers
1 votes
116 views
1 bookmarks
$\sum\limits_{n=1}^\infty\dfrac{\nu(n)}{n^s}=\zeta(s)^2$ for $s$ real
2 answers
1 votes
280 views
Dedekind cuts in Rudin's PMA
1 answers
1 votes
106 views
Question about a proof of FTA in A classical Introduction to modern number theory
1 answers
1 votes
59 views
1 bookmarks
Finding solutions of $z^2=x^2+y^2$ where $\gcd(z, y) =1$
1 answers
1 votes
93 views
1 bookmarks
I need help proving a statement about rational roots
2 answers
1 votes
277 views
Find the roots of the equation $(1+xi)^n+(1-xi)^n=0$
1 answers
0 votes
79 views
Proof that if $a$ is an integer greater than $1,$ then there are infinitely many primes of the form $p=a^n(a+1)-1,$ where $n$ is a positive integer
1 answers
-1 votes
36 views
If $x,y,a_1,\ldots,a_n\in\mathbb Z$ and $a_1,\ldots,a_n\in[x,y],$ then $a_1=x,a_2=x+1,\ldots,a_n=y$ (proof verification)
1 answers
-2 votes
55 views
How to find $x$ in $\left\lfloor{\frac{x-2000}{4}}\right\rfloor+x\equiv0\pmod 7$
1 answers
-2 votes
36 views
If $a$ is a real number greater than one and $x$ and $y$ are rationals with $x\leq y$ then $a^x\leq a^y$