A165760 a(n) = (16-9*8^n)/7.

1, -8, -80, -656, -5264, -42128, -337040, -2696336, -21570704, -172565648, -1380525200, -11044201616, -88353612944, -706828903568, -5654631228560, -45237049828496, -361896398627984, -2895171189023888, -23161369512191120

Offset: 0

Author

Philippe Deléham, Sep 26 2009

Keywords

• easy
• sign

Links

• G. C. Greubel, Table of n, a(n) for n = 0..500
• Index entries for linear recurrences with constant coefficients, signature (9,-8).

Crossrefs

Cf. A112555.

Programs

Mathematica

(16-9*8^Range[0, 50])/7 (* or *) LinearRecurrence[{9, -8}, {1, -8}, 50] (* G. C. Greubel, Apr 07 2016 *)

PARI

x='x+O('x^99); Vec((1-17*x)/(1-9*x+8*x^2)) \\ Altug Alkan, Apr 08 2016

Formula

a(n) = 8*a(n-1)-16, a(0)=1.

a(n) = 9*a(n-1) - 8*a(n-2), a(0)= 1, a(1)= -8, for n>1.

G.f.: (1-17x)/(1-9x+8x^2).

a(n) = Sum_{0<=k<=n} A112555(n,k)*(-9)^(n-k).

E.g.f.: (1/7)*(16*exp(x) - 9*exp(8*x)). - G. C. Greubel, Apr 07 2016