0,2

If (2n+1)>5 is not divisible by 5 and (2n+1) divides a(n) then (2n+1) is often prime. What is the set of exceptions?

Table of n, a(n) for n=0..18.

(PARI) a(n)=sum(k=0, n, binomial(n+k, k)*fibonacci(n+k))

Sequence in context: A155640 A024217 A199679 * A066221 A332468 A134272

Adjacent sequences: A118723 A118724 A118725 * A118727 A118728 A118729

nonn

Benoit Cloitre, May 21 2006

approved