A384974 G.f. A(x) satisfies A(x) = 1 + x*A(x)/A(-x*A(x)^3)^2.
1, 1, 3, 8, 25, 57, 22, -1003, -9967, -67627, -394013, -1958808, -7869346, -17261270, 104411359, 1931214493, 19188604691, 153913872501, 1080677292567, 6709916699425, 35489004465351, 135918792966633, -9832967202556, -7535958768199373, -106301159541342282
Offset: 0
Keywords
Crossrefs
Column k=1 of A384977.
Programs
-
PARI
a(n, k=-1) = if(n*k==0, 0^n, (-1)^n*k*sum(j=1, n, binomial(-3*n+3*j+k-1, j-1)*a(n-j, 2*j)/j));
Formula
See A384977.