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A074524
a(n) = 1^n + 7^n + 9^n.
0
3, 17, 131, 1073, 8963, 75857, 649091, 5606513, 48811523, 427774097, 3769259651, 33358386353, 296270823683, 2638754838737, 23555015527811, 210638693604593, 1886253119421443, 16909812213653777, 151723048894909571
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Dec 26 2008: (Start)
G.f.: 1/(1-x) + 1/(1-7*x) + 1/(1-9*x).
E.g.f.: e^x + e^(7*x) + e^(9*x). (End)
a(n) = 16*a(n-1) - 63*a(n-2) + 48 with a(0)=3, a(1)=17. - Vincenzo Librandi, Jul 21 2010
MATHEMATICA
Table[1^n + 7^n + 9^n, {n, 0, 20}]
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved