A166153 a(n) = (7^n+14*(-8)^n)/15.

1, -7, 63, -455, 3983, -29463, 252511, -1902439, 16043055, -122579639, 1020990719, -7885450503, 65060930767, -506646158935, 4150058281887, -32522243182247, 264925506967919, -2086171125173751, 16921999515377215

Offset: 0

Author

Philippe Deléham, Oct 08 2009

Keywords

• easy
• sign

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (-1, 56).

Crossrefs

Cf. A112555, A166035, A166036, A166149, A166152.

Programs

Mathematica

LinearRecurrence[{-1, 56}, {1, -7}, 50] (* G. C. Greubel, May 01 2016 *)

Formula

a(n) = 56*a(n-2)-a(n-1), a(0)= 1, a(1)= -7, for n>1.

G.f.: (1-6*x)/(1+x-56*x^2).

a(n) = Sum_{k=0..n} A112555(n,k)*(-8)^k.

E.g.f.: (1/15)*(exp(7*x) + 14*exp(-8*x)). - G. C. Greubel, May 01 2016