A194691 - OEIS

A194691

G.f. A(x) satisfies A(x) = 1 + Sum_{n>=1} A(x)^n * x^n*(1 + x^n)^n.

1, 1, 3, 7, 23, 71, 245, 844, 3031, 11023, 40890, 153456, 582868, 2234096, 8634800, 33607223, 131619098, 518285703, 2050849866, 8150520122, 32519072805, 130205541912, 523022475545, 2107119140699, 8511959958494, 34470547999253, 139914333878668, 569112388312690

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..27.

EXAMPLE

G.f.: A(x) = 1 + x + 3*x^2 + 7*x^3 + 23*x^4 + 71*x^5 + 245*x^6 +...

where

A(x) = 1 + A(x)*x*(1+x) + A(x)^2*x^2*(1+x^2)^2 + A(x)^3*x^3*(1+x^3)^3 +...

PROG

(PARI) {a(n)=local(A=1+x); for(i=1, n, A=1+sum(m=1, n, A^m*x^m*(1+x^m+x*O(x^n))^m)); polcoeff(A, n)}

CROSSREFS