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A155620
9^n+4^n-1.
1
1, 12, 96, 792, 6816, 60072, 535536, 4799352, 43112256, 387682632, 3487832976, 31385253912, 282446313696, 2541932937192, 22877060890416, 205892205836472, 1853024483819136, 16677198879535752, 150094704016475856
OFFSET
0,2
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
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 27 2009
STATUS
approved