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A074622
a(n) = 7^n + 8^n.
3
2, 15, 113, 855, 6497, 49575, 379793, 2920695, 22542017, 174571335, 1356217073, 10567261335, 82560763937, 646644824295, 5076269583953, 39931933598775, 314707907280257, 2484430327672455, 19642812107392433, 155514083261229015
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Jan 11 2009: (Start)
G.f.: 1/(1-7*x) + 1/(1-8*x).
E.g.f.: e^(7*x) + e^(8*x). (End)
a(n) = 15*a(n-1) - 56*a(n-2) with a(0)=2, a(1)=15. - Vincenzo Librandi, Jul 21 2010
MATHEMATICA
Table[7^n + 8^n, {n, 0, 20}]
LinearRecurrence[{15, -56}, {2, 15}, 20] (* Harvey P. Dale, Jun 08 2022 *)
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 26 2002
STATUS
approved