login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Expansion of x*(1+5*x)/((1+2*x+1)*(1-4*x)).
0

%I #14 Jan 01 2024 11:42:14

%S 0,1,7,22,100,376,1552,6112,24640,98176,393472,1572352,6292480,

%T 25163776,100667392,402644992,1610629120,6442418176,25769869312,

%U 103079084032,412317122560,1649266917376,6597070815232,26388276969472

%N Expansion of x*(1+5*x)/((1+2*x+1)*(1-4*x)).

%F a(n) = 2*a(n-1) + 8*a(n-2) for n>=3; a(0)=0, a(1)=1, a(2)=7.

%F O.g.f.: x*(1+5*x)/((1+2*x+1)*(1-4*x)). - _R. J. Mathar_, Dec 05 2007

%p a[0]:=0: a[1]:=1: a[2]:=7: for n from 3 to 26 do a[n]:=2*a[n-1]+8*a[n-2] od: seq(a[n],n=0..26);

%K nonn,easy

%O 0,3

%A _Roger L. Bagula_, Apr 18 2006

%E Edited by _N. J. A. Sloane_, May 13 2006

%E New name using g.f. from _Joerg Arndt_, Jan 01 2024