A186633 G.f.: Product_{n>=1} (1 + n^n*x^n)^(1/n).

1, 1, 2, 11, 71, 705, 8470, 127284, 2231342, 45505041, 1048341387, 27059612615, 771505041184, 24109351520196, 818862556900962, 30044548635160841, 1184027932446520895, 49883835880381353808, 2237276988838875420087

Offset: 0

Author

Paul D. Hanna, Mar 19 2011

Keywords

• nonn

Examples

			G.f.: A(x) = 1 + x + 2*x^2 + 11*x^3 + 71*x^4 + 705*x^5 +...
A(x) = (1 + x) *(1 + 4*x^2)^(1/2) *(1 + 27*x^3)^(1/3) *(1 + 256*x^4)^(1/4) *...
		

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..370

Crossrefs

Cf. variant: A023881.

Programs

PARI

{a(n)=if(n<0, 0, polcoeff(prod(k=1, n, (1+k^k*x^k+x*O(x^n))^(1/k)), n))}

Formula

a(n) ~ n^(n-1). - Vaclav Kotesovec, Nov 06 2014