A328604 G.f.: (1 + 7*x) / (1 - 2*x - 9*x^2).

1, 9, 27, 135, 513, 2241, 9099, 38367, 158625, 662553, 2752731, 11468439, 47711457, 198638865, 826680843, 3441111471, 14322350529, 59614704297, 248130563355, 1032793465383, 4298762000961, 17892665190369, 74474188389387, 309982363492095, 1290232422488673, 5370306116406201

Offset

0,2

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (2,9).

Formula

a(n) = 2*a(n-1) + 9*a(n-2) for n>1. - Colin Barker, Oct 21 2019

a(n)/a(n-1) ~ 1 + sqrt(10).

Prog

(PARI) Vec((1 + 7*x) / (1 - 2*x - 9*x^2) + O(x^30)) \\ Colin Barker, Dec 13 2019

Crossrefs

Sequence in context: A126322 A020279 A339725 * A357667 A230185 A340235

Adjacent sequences: A328601 A328602 A328603 * A328605 A328606 A328607

Keyword

nonn,easy

Author

Kyle MacLean Smith, Oct 20 2019

Extensions

Edited by N. J. A. Sloane, Dec 05 2019

Status

approved