A173391 a(n) = 6n + 3^n.

9, 21, 45, 105, 273, 765, 2229, 6609, 19737, 59109, 177213, 531513, 1594401, 4783053, 14348997, 43046817, 129140265, 387420597, 1162261581, 3486784521, 10460353329, 31381059741, 94143178965, 282429536625, 847288609593

Offset

1,1

Links

Table of n, a(n) for n=1..25.

Index entries for linear recurrences with constant coefficients, signature (5, -7, 3).

Formula

From R. J. Mathar, Feb 21 2010: (Start)

a(n) = 5*a(n-1) - 7*a(n-2) + 3*a(n-3).

G.f.: -3*x*(3-8*x+x^2)/((3*x-1) * (x-1)^2). (End)

Prog

(Magma) [6*n+3^n: n in [1..500]] // Vincenzo Librandi, Dec 04 2010

Crossrefs

Sequence in context: A135187 A246318 A277715 * A259243 A241747 A133762

Adjacent sequences: A173388 A173389 A173390 * A173392 A173393 A173394

Keyword

nonn

Author

Mickel Tolbert (princess_rockstar34(AT)yahoo.com), Feb 17 2010

Extensions

Extended by R. J. Mathar and Vincenzo Librandi, Feb 21 2010

Status

approved