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A091865 G.f. satisfies A(x) = 1 + x*A(x)*A(x^2)*A(x^3)*...*A(x^n)*... 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..34.

FORMULA

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

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

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

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Last modified October 22 23:18 EDT 2018. Contains 316518 sequences. (Running on oeis4.)