A074520 1^n + 6^n + 7^n.

3, 14, 86, 560, 3698, 24584, 164306, 1103480, 7444418, 50431304, 342941426, 2340123800, 16018069538, 109949704424, 756587236946, 5217746494520, 36054040477058, 249557173431944, 1729973554578866, 12008254925383640

Offset

0,1

Links

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (14,-55,42).

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

Cf. A001550, A001576, A034513, A001579, A074501 - A074580.

Sequence in context: A317060 A308940 A276313 * A127715 A307440 A087912

Adjacent sequences: A074517 A074518 A074519 * A074521 A074522 A074523

Keyword

nonn,easy

Author

Robert G. Wilson v, Aug 23 2002

Status

approved