A384574 G.f. A(x) satisfies A(x) = 1 + x * A(x*A(x)^4).
1, 1, 1, 5, 23, 155, 1236, 11286, 116333, 1329433, 16630343, 225606826, 3294976854, 51496560764, 856858516809, 15112857079891, 281479726839851, 5517842789917283, 113510479973132860, 2444032094604379100, 54948814775692303024, 1287258966133883349701
Offset: 0
Keywords
Programs
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PARI
a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(4*n-4*j+k, j)/(4*n-4*j+k)*a(n-j, j)));
Formula
See A384582.