%I #3 Mar 30 2012 18:36:41
%S 1,1,2,3,7,8,15,19,37,42,66,76,122,114,148,90,77,-213,-574,-1511,
%T -2860,-5773,-10209,-18310,-30884,-52778,-87051,-143621,-232157,
%U -375464,-599112,-953504,-1504430,-2368510,-3706276,-5782850,-8984526,-13924596,-21511458,-33151454,-50964864,-78187890
%N Main diagonal of triangle A097094; g.f. A(x) satisfies A(x)/(1-x-x^2) = A(x^2)^2/(1-x-x^3)^2.
%F G.f.: A(x)/(1-x-x^2) = g.f. of A097096 (row sums of A097094); G.f.: A(x^2)/(1-x-x^3) = g.f. of A097097 (antidiagonal sums of A097094).
%o (PARI) {a(n)=local(A=1+x+x*O(x^n));for(i=0,n+2, B=subst(A^2,x,x^2);A=(A+B*(1-x-x^2)/(1-x-x^3+x*O(x^n))^2)/2); round(polcoeff(A+x*O(x^n),n))}
%Y Cf. A097094, A097096, A097097.
%K sign
%O 0,3
%A _Paul D. Hanna_, Jul 26 2004
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