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

Author

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

Keywords

• nonn
• easy
• less

Links

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

Crossrefs

Cf. A015518.

Programs

Mathematica

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

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

Extensions

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