A083578 a(n) = (6^n + (-4)^n)/2.

1, 1, 26, 76, 776, 3376, 25376, 131776, 872576, 4907776, 30757376, 179301376, 1096779776, 6496792576, 39316299776, 234555621376, 1412702437376, 8454739787776, 50814338072576, 304542431051776, 1828628975845376

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Index entries for linear recurrences with constant coefficients, signature (2,24).

Formula

a(n) = (6^n + (-4)^n)/2.

G.f.: (1-x)/((1+4x)(1-6x)).

E.g.f.: (exp(6x) + exp(-4x))/2.

Mathematica

LinearRecurrence[{2, 24}, {1, 1}, 30] (* Harvey P. Dale, Nov 29 2017 *)

Crossrefs

Cf. A083579. First differences of A051958.

Sequence in context: A139698 A124719 A126380 * A173307 A042326 A042328

Adjacent sequences: A083575 A083576 A083577 * A083579 A083580 A083581

Keyword

easy,nonn

Author

Paul Barry, Apr 30 2003

Status

approved