login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

a(n) = (8^n+16*(-9)^n)/17.
2

%I #11 May 02 2016 00:24:33

%S 1,-8,80,-656,6416,-53648,515600,-4378256,41501456,-356735888,

%T 3344840720,-29029824656,269858356496,-2360005731728,21789807399440,

%U -191710220083856,1760576352843536,-15563712198881168

%N a(n) = (8^n+16*(-9)^n)/17.

%H G. C. Greubel, <a href="/A166157/b166157.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (-1, 72).

%F a(n) = 72*a(n-2)-a(n-1), a(0)= 1, a(1)= -8, for n>1.

%F G.f.: (1-7x)/(1+x-72*x^2).

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

%F E.g.f.: (1/17)*(exp(8*x) + 16*exp(-9*x)). - _G. C. Greubel_, May 01 2016

%t LinearRecurrence[{-1,72},{1,-8},20] (* _Harvey P. Dale_, Jun 23 2012 *)

%o (PARI) a(n)=(8^n+16*(-9)^n)/17 \\ _Charles R Greathouse IV_, May 02 2016

%Y Cf. A166035, A166036, A166149, A166152, A166153.

%K easy,sign

%O 0,2

%A _Philippe Deléham_, Oct 08 2009