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A052802
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A simple grammar.
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2
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1, 1, 5, 47, 660, 12414, 293552, 8374806, 280064600, 10747277832, 465597887592, 22479948822792, 1197060450322800, 69699159437088960, 4405397142701855232, 300408348609092268144, 21983809533066553697280
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 760
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FORMULA
| Contribution from Paul D. Hanna (pauldhanna(AT)juno.com), Aug 28 2008: (Start)
E.g.f. satisfies: A(x*(1 + log(1-x))) = 1/(1 + log(1-x)).
E.g.f. satisfies: A(x) = 1/(1 + log(1 - x*A(x))).
E.g.f.: A(x) = (1/x)*Series_Reversion[x + x*log(1-x)]. (End)
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EXAMPLE
| E.g.f.: A(x) = 1 + x + 5*x^2/2! + 47*x^3/3! + 660*x^4/4! +... [From Paul D. Hanna (pauldhanna(AT)juno.com), Aug 28 2008]
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MAPLE
| spec := [S, {C=Cycle(B), S=Sequence(C), B=Prod(S, Z)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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PROG
| (PARI) a(n)=n!*polcoeff((1/x)*serreverse(x+x*log(1-x +x*O(x^n))), n) [From Paul D. Hanna (pauldhanna(AT)juno.com), Aug 28 2008]
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CROSSREFS
| Cf. A052819. [From Paul D. Hanna (pauldhanna(AT)juno.com), Aug 28 2008]
Sequence in context: A180254 A127696 A088691 * A098799 A089155 A086555
Adjacent sequences: A052799 A052800 A052801 * A052803 A052804 A052805
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KEYWORD
| easy,nonn
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AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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