%I A113180
%S A113180 1,2,4,8,20,56,160,448,1240,3440,9632,27200,77216,219840,627200,1793024,
%T A113180 5136480,14743232,42390400,122064640,351951232,1015990528,2936079360,
%U A113180 8493340672,24591589120,71262291456,206666232832,599778166784
%N A113180 Expansion of 1/sqrt((1-2x)^2-8x^4).
%C A113180 In general, 1/sqrt((1-a*x)^2-4*b*x^4) expands to sum{k=0..floor(n/2), 
               C(n-2k,k)C(n-3k,k)b^k*a^(n-4k)}.
%F A113180 a(n)=sum{k=0..floor(n/2), C(n-2k, k)C(n-3k, k)2^(n-3k)}.
%Y A113180 Cf. A098482, A113179.
%Y A113180 Sequence in context: A000980 A123611 A082279 this_sequence A000116 A006407 
               A100447
%Y A113180 Adjacent sequences: A113177 A113178 A113179 this_sequence A113181 A113182 
               A113183
%K A113180 easy,nonn
%O A113180 0,2
%A A113180 Paul Barry (pbarry(AT)wit.ie), Oct 16 2005