%I A104629
%S A104629 1,2,6,18,57,186,622,2120,7338,25724,91144,325878,1174281,4260282,
%T A104629 15548694,57048048,210295326,778483932,2892818244,10786724388,
%U A104629 40347919626,151355847012,569274150156,2146336125648,8110508473252
%N A104629 Expansion of (1-2x-sqrt(1-4x))/(1+2x+sqrt(1-4x))/x^2.
%C A104629 Diagonal sums of A039598. a(n)=A000957(n+3).
%F A104629 a(n)=(1+sum{k=0..n+2, C(k)(-2)^k})/(8(-2)^n)
%Y A104629 Cf. A064310.
%Y A104629 Sequence in context: A125306 A064310 A126983 this_sequence A000957 A125305 
               A148458
%Y A104629 Adjacent sequences: A104626 A104627 A104628 this_sequence A104630 A104631 
               A104632
%K A104629 easy,nonn
%O A104629 0,2
%A A104629 Paul Barry (pbarry(AT)wit.ie), Mar 17 2005