A356506 a(n) = A356500(3*n, n+1) for n >= 0.

1, 6, 120, 3250, 103020, 3587696, 133101836, 5167564380, 207615129579, 8567305854998, 361201849117032, 15498967122249676, 674906101555736960, 29757755664623031984, 1326196334421645347368, 59655785739373960058296, 2705420198806474232850741

Offset: 0

Author

Paul D. Hanna, Aug 09 2022

Keywords

• nonn

Comments

Triangle A356500 describes the coefficients in G(x,y) that satisfies: y = Sum_{n=-oo..+oo} (-x)^(n^2) * G(x,y)^((n-1)^2).

Crossrefs

Cf. A356500, A356504, A356505.

Programs

PARI

{A356500(n,k) = my(A=[y],M); for(i=1,n, A = concat(A,0); M = ceil(sqrt(n+1));
A[#A] = -polcoeff( sum(m=-M,M, (-x)^(m^2)*Ser(A)^((m-1)^2)), #A-1)); polcoeff(A[n+1],k,y) }
for(n=0,20, print1( A356500(3*n, n+1),", "))