A074540 a(n) = 2^n + 5^n + 9^n.

3, 16, 110, 862, 7202, 62206, 547130, 4861222, 43437602, 389374126, 3496551050, 31429889782, 282673681202, 2543086539646, 22882895986970, 205921649705542, 1853172776808002, 16677944639250766, 150098449994526890, 1350870791159844502, 12157760826489618002

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (16,-73,90).

Formula

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

G.f.: 1/(1-2*x) + 1/(1-5*x) + 1/(1-9*x).

E.g.f.: exp(2*x) + exp(5*x) + exp(9*x). (End)

a(n) = 16*a(n-1) - 73*a(n-2) + 90*a(n-3) for n > 2. - Wesley Ivan Hurt, Oct 06 2017

Maple

A074540:=n->2^n + 5^n + 9^n: seq(A074540(n), n=0..30); # Wesley Ivan Hurt, Oct 06 2017

Mathematica

Table[2^n + 5^n + 9^n, {n, 0, 20}]

Prog

(Magma) [2^n + 5^n + 9^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011

Crossrefs

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

Sequence in context: A191800 A286764 A180609 * A353192 A218680 A141003

Adjacent sequences: A074537 A074538 A074539 * A074541 A074542 A074543

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved