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A074505
a(n) = 1^n + 2^n + 9^n.
0
3, 12, 86, 738, 6578, 59082, 531506, 4783098, 43046978, 387421002, 3486785426, 31381061658, 282429540578, 2541865836522, 22876792471346, 205891132127418, 1853020188917378, 16677181699797642, 150094635297261266
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Dec 26 2008: (Start)
G.f.: 1/(1-x) + 1/(1-2*x) + 1/(1-9*x).
E.g.f.: e^x + e^(2*x) + e^(9*x). (End)
a(n) = 11*a(n-1) - 18*a(n-2) + 8 with a(0)=3, a(1)=12. - Vincenzo Librandi, Jul 21 2010
MATHEMATICA
Table[1^n + 2^n + 9^n, {n, 0, 20}]
LinearRecurrence[{12, -29, 18}, {3, 12, 86}, 30] (* Harvey P. Dale, Aug 28 2019 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved