A155620 9^n+4^n-1.

1, 12, 96, 792, 6816, 60072, 535536, 4799352, 43112256, 387682632, 3487832976, 31385253912, 282446313696, 2541932937192, 22877060890416, 205892205836472, 1853024483819136, 16677198879535752, 150094704016475856

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Index entries for linear recurrences with constant coefficients, signature (14,-49,36).

Formula

G.f.: 1/(1-9*x)+1/(1-4*x)-1/(1-x). E.g.f.: e^(9*x)+e^(4*x)-e^x.

a(n)=13*a(n-1)-36*a(n-2)-24 with a(0)=1, a(1)=12 [From Vincenzo Librandi, Jul 21 2010]

a(0)=1, a(1)=12, a(2)=96, a(n)=14*a(n-1)-49*a(n-2)+36*a(n-3). - Harvey P. Dale, Feb 02 2015

Mathematica

LinearRecurrence[{14, -49, 36}, {1, 12, 96}, 30] (* Harvey P. Dale, Feb 02 2015 *)

Crossrefs

A155588, A155599, A155607 - A155619.

Sequence in context: A204623 A270568 A223151 * A219438 A219139 A059375

Adjacent sequences: A155617 A155618 A155619 * A155621 A155622 A155623

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 27 2009

Status

approved