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A074520
1^n + 6^n + 7^n.
1
3, 14, 86, 560, 3698, 24584, 164306, 1103480, 7444418, 50431304, 342941426, 2340123800, 16018069538, 109949704424, 756587236946, 5217746494520, 36054040477058, 249557173431944, 1729973554578866, 12008254925383640
OFFSET
0,1
FORMULA
G.f.:1/(1-x)+1/(1-6*x)+1/(1-7*x). E.g.f.: e^x+e^(6*x)+e^(7*x). [Mohammad K. Azarian, Dec 26 2008]
a(n) = 13*a(n-1) - 42*a(n-2) + 30, n>1. [Gary Detlefs, Jun 21 2010]
a(n) = A074619(n) + 1. - Michel Marcus, Nov 11 2013
MAPLE
A074520:=n->1^n + 6^n + 7^n; seq(A074520(n), n=0..100); # Wesley Ivan Hurt, Nov 11 2013
MATHEMATICA
Table[1 + 6^n + 7^n, {n, 0, 20}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved