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Search: id:A110143
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| 1, 1, 4, 11, 43, 161, 901, 5579, 43206, 378360, 3742738, 40853520, 488029621, 6323154547, 88308425755, 1322120265238, 21122364398761, 358647945023885, 6449299885654827, 122436442904193940, 2447046870232798369
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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Row n of triangle A110141 lists the denominators of unit fraction coefficients of the products of {c_k}, in ascending order by indices of {c_k}, in the coefficient of x^n in exp(Sum_{k>=1} c_k/k*x^k). There are A000041(n) terms in row n of triangle A110141.
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REFERENCES
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J. H. Kwak and J. Lee, Enumeration of graph coverings, surface branched coverings and related group theory, in Combinatorial and Computational Mathematics (Pohang, 2000), ed. S. Hong et al., World Scientific, Singapore 2001, pp. 97-161. Appears to contain this sequence in Table 2. [Added by N. J. A. Sloane, Nov 12 2009]
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FORMULA
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G.f.: B(x)*B(2*x^2)*B(3*x^3)*..., where B(x) is g.f. of A000142. - Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 18 2007
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CROSSREFS
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Cf. A110141, A000041.
Cf. A096161.
Sequence in context: A149277 A149278 A163133 this_sequence A149279 A149280 A149281
Adjacent sequences: A110140 A110141 A110142 this_sequence A110144 A110145 A110146
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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), Jul 14 2005
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