A074536 a(n) = 2^n + 4^n + 9^n.

3, 15, 101, 801, 6833, 60105, 535601, 4799481, 43112513, 387683145, 3487834001, 31385255961, 282446317793, 2541932945385, 22877060906801, 205892205869241, 1853024483884673, 16677198879666825, 150094704016738001

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,-62,72).

Formula

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

G.f.: 1/(1-2*x) + 1/(1-4*x) + 1/(1-9*x).

E.g.f.: exp(2*x) + exp(4*x) + exp(9*x). (End)

Mathematica

Table[2^n + 4^n + 9^n, {n, 0, 20}]

Prog

(Magma) [2^n + 4^n + 9^n: n in [0..25]]; // Vincenzo Librandi, Jun 11 2011

Crossrefs

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

Sequence in context: A350954 A196962 A074521 * A152093 A109777 A242003

Adjacent sequences: A074533 A074534 A074535 * A074537 A074538 A074539

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved