A213435 G.f. A(x) = 1 / (1 - a(0)*x / (1 - a(1)*x / (1 - a(2)*x / ...))).

1, 1, 2, 6, 32, 620, 259960, 62059718088, 3840971361624607057216, 14752998887519276350335088653216965113845136

Offset: 0

Author

Michael Somos, Jun 11 2012

Keywords

• nonn

Examples

			1 + x + 2*x^2 + 6*x^3 + 32*x^4 + 620*x^5 + 259960*x^6 + 62059718088*x^7 + ...
		

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..13

Programs

PARI

{a(n) = local(A, y='y); if( n<0, 0, A = y; for( k=0, n, A = subst( A, y, 1 / (1 - x*y* subst( polcoeff( A + x*O(x^k), k), y, 1)))); simplify( polcoeff( A + x*O(x^n), n)))}