A074541 a(n) = 2^n + 6^n + 7^n.

3, 15, 89, 567, 3713, 24615, 164369, 1103607, 7444673, 50431815, 342942449, 2340125847, 16018073633, 109949712615, 756587253329, 5217746527287, 36054040542593, 249557173563015, 1729973554841009, 12008254925907927

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (15,-68,84).

Formula

From Mohammad K. Azarian, Dec 27 2008: (Start)

G.f.: 1/(1-2*x) + 1/(1-6*x) + 1/(1-7*x).

E.g.f.: exp(2*x) + exp(6*x) + exp(7*x). (End)

Mathematica

Table[2^n + 6^n + 7^n, {n, 0, 20}]

Prog

(Magma) [2^n + 6^n + 7^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011

Crossrefs

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

Sequence in context: A127785 A287511 A231257 * A368974 A074550 A205576

Adjacent sequences: A074538 A074539 A074540 * A074542 A074543 A074544

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved