A385984 a(0) = 1; a(n) = Sum_{k=0..n-1} (-2)^k * binomial(n-1,k) * a(k) * a(n-1-k).
1, 1, -1, -9, 57, 1353, -38313, -2796417, 339169041, 90178580529, -45316930884849, -46917802526957721, 95533688640942728073, 392558870984301366092217, -3210372581644929567134113497, -52647023496165910533698485658193, 1724296469950918188679460249845485729
Offset: 0
Keywords
Programs
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PARI
a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=0, i-1, (-2)^j*binomial(i-1, j)*v[j+1]*v[i-j])); v;
Formula
E.g.f. A(x) satisfies A'(x) = A(x) * A(-2*x).