MathDB
Function

Source: 14-th Iranian Mathematical Olympiad 1996/1997

October 17, 2005
functionalgebra proposedalgebra

Problem Statement

Determine all functions f:N0N0{1}f : \mathbb N_0 \rightarrow \mathbb N_0 - \{1\} such that f(n+1)+f(n+3)=f(n+5)f(n+7)1375,nN.f(n + 1) + f(n + 3) = f(n + 5)f(n + 7) - 1375, \qquad \forall n \in \mathbb N.