# Not fibbo

Author: mathforces
Problem has been solved: 52 times

Русский язык | English Language

We call the sequence $a_n$ Fibo if it increases, consists only of positive integer numbers and each element starting from the third is equal to the sum of the two previous ones. For some fibo sequence $x_n$ is known that $x_7 = 120$. Find $x_{10}$.