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A156908 G.f.: A(x) = 1 + x*exp( Sum_{k>=1} [A(3^k*x) - 1]^k/k ). 2
1, 1, 3, 72, 10899, 13775400, 185126087574, 25804839804745266, 34576186149297464460939, 431016348991655088520874274528, 49345807665910247245278532420622266770 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Conjectured to consist entirely of integers.

LINKS

Table of n, a(n) for n=0..10.

EXAMPLE

G.f.: A(x) = 1 + x + 3*x^2 + 72*x^3 + 10899*x^4 + 13775400*x^5 +...

...

A(x) = 1 + x*exp( [A(3x)-1] + [A(9x)-1]^2/2 + [A(27x)-1]^3/3 +... ).

PROG

(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=1, n, A=1+x*exp(sum(k=1, n, (subst(A, x, 3^k*x+x*O(x^n))-1)^k/k))); polcoeff(A, n)}

CROSSREFS

Cf. A156907.

Sequence in context: A332747 A202948 A213986 * A182517 A135866 A307925

Adjacent sequences:  A156905 A156906 A156907 * A156909 A156910 A156911

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Mar 04 2009

STATUS

approved

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Last modified August 5 04:03 EDT 2021. Contains 346457 sequences. (Running on oeis4.)