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8, 114, 667, 2504, 7191, 17266, 36482, 70050, 124882, 209834, 335949, 516700, 768233, 1109610, 1563052, 2154182, 2912268, 3870466, 5066063, 6540720, 8340715, 10517186, 13126374, 16229866, 19894838, 24194298, 29207329
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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REFERENCES
| I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983,(2.3.14).
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FORMULA
| G.f.: (x+2)*(2*x^4+8*x^3+36*x^2+31*x+4)/(1-x)^6. 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
| Cf. dumbbells: A002940, A002941, A002889, A046741, A055608, A062123-A062127.
Sequence in context: A092084 A099715 A023814 * A113670 A156468 A056988
Adjacent sequences: A062123 A062124 A062125 * A062127 A062128 A062129
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KEYWORD
| easy,nonn
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Jun 04 2001
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EXTENSIONS
| More terms from Larry Reeves (larryr(AT)acm.org), Jun 06 2001
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