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A074539
a(n) = 2^n + 5^n + 8^n.
1
3, 15, 93, 645, 4737, 35925, 277833, 2175405, 17168097, 136171365, 1083508473, 8638764765, 68963621457, 550976525205, 4404150043113, 35214889699725, 281627564666817, 2252562753269445, 18018213207009753, 144134261562708285
OFFSET
0,1
LINKS
D. Suprijanto, I. W. Suwarno, Observation on Sums of Powers of Integers Divisible by 3k-1, Applied Mathematical Sciences, Vol. 8, 2014, no. 45, pp. 2211-2217.
FORMULA
From Mohammad K. Azarian, Dec 27 2008: (Start)
G.f.: 1/(1-2*x) + 1/(1-5*x) + 1/(1-8*x).
E.g.f.: exp(2*x) + exp(5*x) + exp(8*x). (End)
MATHEMATICA
Table[2^n + 5^n + 8^n, {n, 0, 20}]
PROG
(Magma) [2^n + 5^n + 8^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved