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A074529
a(n) = 2^n + 3^n + 7^n.
1
3, 12, 62, 378, 2498, 17082, 118442, 825858, 5771618, 40373802, 282535322, 1977505938, 13841822738, 96890612922, 678227872202, 4747575891618, 33232973681858, 232630643258442, 1628413985593082, 11398896348158898
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Dec 27 2008: (Start)
G.f.: 1/(1-2*x) + 1/(1-3*x) + 1/(1-7*x).
E.g.f.: exp(2*x) + exp(3*x) + exp(7*x). (End)
MATHEMATICA
Table[2^n + 3^n + 7^n, {n, 0, 20}]
LinearRecurrence[{12, -41, 42}, {3, 12, 62}, 20] (* Harvey P. Dale, Mar 29 2020 *)
PROG
(Magma) [2^n + 3^n + 7^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved