A372500 G.f. A(x) satisfies A(A(A(x))) = Sum_{k>=1} k^2 * 9^(k-1) * x^k.
0, 1, 12, -45, 1404, -33048, 684288, -5847309, -440129376, 30809872071, -952939532952, -1846906652457, 1545045542366472, -30949156972076031, -4367665752590389608, 253458876292612253442, 14695464346775699515704, -2012792131604632851142020
Offset: 0
Keywords
Examples
A(A(x)) = x + 24*x^2 + 198*x^3 + 1836*x^4 + 8667*x^5 - 139968*x^6 + 11814903*x^7 - 371755008*x^8 + ...