proposition: Lemma FR_fib_sum6 i: FR(fib (i + 5) + 2) = (i.+3)./2.
proof: Proof. by rewrite (FR_fib_sum1 i (leqnSn 2)) addn0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path fintype div bigop binomial) mathcomp(prime finset ssralg ssrnum ssrint)