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A074538
a(n) = 2^n + 5^n + 7^n.
1
3, 14, 78, 476, 3042, 19964, 133338, 901796, 6155682, 42307244, 292241898, 2026156916, 14085431922, 98109721724, 684326604858, 4778079120836, 33385518525762, 233393453571404, 1632228295438218, 11417968672225556, 79887633730301202, 559022701243584284
OFFSET
0,1
FORMULA
From Mohammad K. Azarian, Dec 27 2008: (Start)
G.f.: 1/(1-2*x)+1/(1-5*x)+1/(1-7*x).
E.g.f.: exp(2*x)+exp(5*x)+exp(7*x). (End)
a(n) = 14*a(n-1) - 59*a(n-2) + 70*a(n-3) for n > 2. - Wesley Ivan Hurt, Oct 06 2017
MAPLE
A074538:=n->2^n+5^n+7^n: seq(A074538(n), n=0..30); # Wesley Ivan Hurt, Oct 06 2017
MATHEMATICA
Table[2^n + 5^n + 7^n, {n, 0, 20}]
LinearRecurrence[{14, -59, 70}, {3, 14, 78}, 20] (* Harvey P. Dale, Dec 21 2016 *)
PROG
(Magma) [2^n + 5^n + 7^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 23 2002
STATUS
approved