A120471 a(n) = 6 * A015518(n).

0, 6, 12, 42, 120, 366, 1092, 3282, 9840, 29526, 88572, 265722, 797160, 2391486, 7174452, 21523362, 64570080, 193710246, 581130732, 1743392202, 5230176600, 15690529806, 47071589412, 141214768242, 423644304720, 1270932914166

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Index entries for linear recurrences with constant coefficients, signature (2,3).

Formula

a(n) = 2*a(n-1)+3*a(n-2).

G.f.: 6*x/(1-2*x-3*x^2). - Colin Barker, Jan 29 2012

Mathematica

LinearRecurrence[{2, 3}, {0, 6}, 30] (* Harvey P. Dale, Jun 09 2017 *)

Crossrefs

Cf. A015518.

Sequence in context: A060551 A129113 A048025 * A219522 A034529 A121160

Adjacent sequences: A120468 A120469 A120470 * A120472 A120473 A120474

Keyword

nonn,easy,less

Author

Roger L. Bagula and Gary W. Adamson, Jul 04 2006

Extensions

Edited by N. J. A. Sloane, Dec 04 2006

Status

approved