A091865 G.f. satisfies A(x) = 1 + x*A(x)*A(x^2)*A(x^3)*...*A(x^n)*...

1, 1, 1, 2, 4, 8, 15, 30, 57, 111, 214, 415, 798, 1547, 2983, 5765, 11132, 21510, 41528, 80231, 154940, 299280, 578017, 1116450, 2156280, 4164827, 8044023, 15536655, 30007988, 57958900, 111943844, 216213363, 417602892, 806575889, 1557852990

Offset

0,4

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..210

Formula

G.f.: A(x) = 1 + x * Product_{k>=1} A(x^k).

a(n) ~ c * d^n, where d = 1.93144101206639993844275031844664... and c = 0.29686384114142059645291926346897... - Vaclav Kotesovec, Oct 02 2020

Prog

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

Crossrefs

Cf. A050383.

Sequence in context: A166861 A026023 A077596 * A065494 A134044 A079967

Adjacent sequences: A091862 A091863 A091864 * A091866 A091867 A091868

Keyword

nonn

Author

Paul D. Hanna, Feb 05 2004

Status

approved