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Search: id:A156908
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| A156908 |
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G.f.: A(x) = 1 + x*exp( Sum_{k>=1} [A(3^k*x) - 1]^k/k ). |
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+0
3
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| 1, 1, 3, 72, 10899, 13775400, 185126087574, 25804839804745266, 34576186149297464460939, 431016348991655088520874274528, 49345807665910247245278532420622266770
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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Conjectured to consist entirely of integers.
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EXAMPLE
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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 +... ).
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PROGRAM
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(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)}
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CROSSREFS
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Cf. A156907.
Sequence in context: A089537 A062074 A071645 this_sequence A135866 A006270 A139888
Adjacent sequences: A156905 A156906 A156907 this_sequence A156909 A156910 A156911
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Mar 04 2009
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