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Search: id:A062127
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| 13, 223, 1577, 7018, 23431, 64316, 153190, 327718, 644573, 1185025, 2061259, 3423422, 5467399, 8443318, 12664784, 18518842, 26476669, 37104995, 51078253, 69191458, 92373815, 121703056, 158420506, 203946878, 259898797, 328106053
(list; graph; listen)
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OFFSET
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0,1
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REFERENCES
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I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983,(2.3.14).
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FORMULA
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G.f.: (2*x^6+14*x^5+72*x^4+207*x^3+289*x^2+132*x+13)/(1-x)^7. Generally, g.f. for k-th column of A046741 is coefficient of y^k in expansion of (1-y)/((1-y-y^2)*(1-y)-(1+y)*x).
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CROSSREFS
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Cf. dumbbells: A002940, A002941, A002889, A046741, A055608, A062123-A062127.
Sequence in context: A051180 A143832 A140841 this_sequence A160342 A068120 A050523
Adjacent sequences: A062124 A062125 A062126 this_sequence A062128 A062129 A062130
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KEYWORD
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easy,nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)eunet.rs), Jun 04 2001
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), Jun 06 2001
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