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A074522
a(n) = 1^n + 6^n + 9^n.
0
3, 16, 118, 946, 7858, 66826, 578098, 5062906, 44726338, 397498186, 3547250578, 31743856666, 284606318818, 2554926522346, 22955156619058, 206361317079226, 1855841298759298, 16694108359111306, 150196195253667538
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Dec 26 2008: (Start)
G.f.: 1/(1-x) + 1/(1-6*x) + 1/(1-9*x).
E.g.f.: e^x + e^(6*x) + e^(9*x). (End)
a(n) = 15*a(n-1) - 54*a(n-2) + 40 with a(0)=3, a(1)=16. - Vincenzo Librandi, Jul 21 2010
E.g.f.: A(x)=Q(0); Q(k)=1+(6^k)/(1-(3^k)/((2^k)+(3^k)-(2^k)*x/(x+(9^k)*(k+1)/Q(k+1)))); (continued fraction). - Sergei N. Gladkovskii, Nov 26 2011
MATHEMATICA
Table[1^n + 6^n + 9^n, {n, 0, 20}]
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved