A076684 Odd terms in A027941.

1, 33, 609, 10945, 196417, 3524577, 63245985, 1134903169, 20365011073, 365435296161, 6557470319841, 117669030460993, 2111485077978049, 37889062373143905, 679891637638612257, 12200160415121876737

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Index entries for linear recurrences with constant coefficients, signature (19,-19,1).

Formula

a(n) = F(6n+3) - 1 where F(k) denotes the k-th Fibonacci number.

G.f.: (1+14x+x^2)/((1-x)(1-18x+x^2)).

Mathematica

a[n_] := Fibonacci[6n+3]-1

Prog

(PARI) a(n)=fibonacci(6*n+3)-1
(PARI) a(n)=if(n<0, 0, subst(poltchebi(n)+poltchebi(n+1), x, 9)/5-1)

Crossrefs

Cf. A027941, A000045.

Sequence in context: A282926 A172362 A080597 * A181382 A252926 A225970

Adjacent sequences: A076681 A076682 A076683 * A076685 A076686 A076687

Keyword

nonn,easy

Author

Benoit Cloitre, Oct 25 2002

Status

approved