%I A135520
%S A135520 2,1,8,4,32,16,128,64,512,256,2048,1024,8192,4096,32768,16384,131072,
%T A135520 65536,524288,262144,2097152,1048576,8388608,4194304,33554432,16777216,
%U A135520 134217728,67108864,536870912,268435456,2147483648,1073741824
%N A135520 a(n)=a(n-1)+4a(n-2)-4a(n-3).
%F A135520 O.g.f.: [ -5/(2x-1)+3/(2x+1)]/4. a(n) = [5*2^n+3*(-2)^n]/4. a(2n)=2*A000302(n). 
               a(2n+1)=A000302(n). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               corrected Apr 14 2008
%F A135520 a(n)=(5/4)*2^n+(3/4)*(-2)^n, with n>=0 - Paolo P. Lava (ppl(AT)spl.at), 
               Jun 06 2008
%Y A135520 Cf. A097163, A097164.
%Y A135520 Sequence in context: A104988 A136225 A089460 this_sequence A136230 A004732 
               A011244
%Y A135520 Adjacent sequences: A135517 A135518 A135519 this_sequence A135521 A135522 
               A135523
%K A135520 nonn
%O A135520 0,1
%A A135520 Paul Curtz (bpcrtz(AT)free.fr), Feb 19 2008
%E A135520 More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 23 2008