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A063842
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Number of n-multigraphs on 4 nodes.
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3
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1, 11, 66, 276, 900, 2451, 5831, 12496, 24651, 45475, 79376, 132276, 211926, 328251, 493725, 723776, 1037221, 1456731, 2009326, 2726900, 3646776, 4812291, 6273411, 8087376, 10319375, 13043251, 16342236, 20309716, 25050026, 30679275
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| Vladeta Jovovic, Formulae for the number T(n,k) of n-multigraphs on k nodes
Index to sequences with linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
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FORMULA
| a(n) = 1/4!*(n^6 + 6*n^5 + 24*n^4 + 56*n^3 + 83*n^2 + 70*n + 24).
G.f. = (1 + 3*x + 7*x^2 + 3*x^3 + x^4)*(1+x)/(1-x)^7 \\ - M. F. Hasler, Jan 19 2012
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CROSSREFS
| A row of A063841. Cf. A063843.
Sequence in context: A126479 A139611 A154617 * A162628 A008503 A008493
Adjacent sequences: A063839 A063840 A063841 * A063843 A063844 A063845
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Aug 25 2001
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 02 2001
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