be a rational number with 
and 
.
.
![\[\sum_{k=0}^{n}\binom{2n+1}{2k+1}2^{3k}\]](http://latex.artofproblemsolving.com/d/4/5/d4511807f1e04ac2fa8aae36d65f9e0f5ba11c6f.png)
is not divisible by 
for any integer 
.
is composite, then 
.
consecutive positive integers is divisible by 
such that 
divides 
.![\[A=\frac{(m+3)^{n}+1}{3m}\]](http://latex.artofproblemsolving.com/f/5/8/f58ed8713c887510943d543c89f83640a546401f.png)
is an integer. Prove that 
is odd.
be divisible by 
.
is divisible by 
and 
be natural numbers having the property ![\[n_{2}\; \vert \; 2^{n_{1}}-1, n_{3}\; \vert \; 2^{n_{2}}-1, \cdots, n_{k}\; \vert \; 2^{n_{k-1}}-1, n_{1}\; \vert \; 2^{n_{k}}-1.\]](http://latex.artofproblemsolving.com/2/0/7/20707ef12d0e08bec8067225a9e9128bbc1d2d45.png)
Show that 
.
.
Y by Adventure10, Mango247, and 1 other user
Suppose that 
and 
are complex numbers such that ![\[\frac{x^{n}-y^{n}}{x-y}\]](//latex.artofproblemsolving.com/1/5/1/151455e7373afe6a6f20b415f1353882c5df1952.png)
are integers for some four consecutive positive integers 
. Prove that it is an integer for all positive integers .
and 
are complex numbers such that ![\[\frac{x^{n}-y^{n}}{x-y}\]](http://latex.artofproblemsolving.com/1/5/1/151455e7373afe6a6f20b415f1353882c5df1952.png)
are integers for some four consecutive positive integers 
. Prove that it is an integer for all positive integers .
is four consective integer in this sequence.
so 
where 
so 
so 
)
so 
so
