|
%I #6 Jun 13 2015 00:51:51
%S 1,3,7,20,53,143,385,1036,2789,7507,20207,54392,146409,394095,1060801,
%T 2855400,7685993,20688691,55688567,149899116,403489373,1086088287,
%U 2923466753,7869210964,21181866061,57016065763,153472396895
%N Expansion of (1+x-x^2)/(1-2x-2x^2+x^4).
%C Transform of 2^n under matrix A108756.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,2,0,-1).
%F a(n)=2a(n-1)+2a(n-2)-a(n-4); a(n)=a(n)=sum{k=0..n, binomial(floor((n+k+1)/2)+k, floor((n+k)/2)-k)*2^k}.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Jun 22 2005
|
