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A074562
a(n) = 4^n + 5^n + 7^n.
1
3, 16, 90, 532, 3282, 20956, 137370, 918052, 6220962, 42568876, 293289450, 2030349172, 14102205042, 98176822396, 684595023930, 4779152829892, 33389813427522, 233410633309516, 1632297014652810, 11418243549608212
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Dec 30 2008: (Start)
G.f.: 1/(1-4*x) + 1/(1-5*x) + 1/(1-7*x).
E.g.f.: exp(4*x) + exp(5*x) + exp(7*x). (End)
MATHEMATICA
Table[4^n + 5^n + 7^n, {n, 0, 20}]
PROG
(Magma) [4^n + 5^n + 7^n: n in [0..20]]; // Vincenzo Librandi, Aug 25 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved