The Fibonacci sequence goes F(0)=0, F(1)=1, and for n>1, F(n)=F(n-1)+F(n-2).
Show that for every positive integer m there exists an integer n>0 such that m divides F(n).
(In reply to
re(3): Proof--Quick fix by armando)
What do you mean by "my question"?
I realise now that each letter in Tristan's proof refers to a pair of consecutive numbers.