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Search: id:A000489
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| A000489 |
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Card matching.
(Formerly M5025 N2168)
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+0
4
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| 1, 16, 435, 7136, 99350, 1234032, 14219212, 155251840, 1628202762, 16550991200, 164111079110, 1594594348800, 15235525651840, 143518352447680, 1335670583147400, 12301278983461376, 112264111607438906
(list; graph; listen)
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OFFSET
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1,2
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 193.
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LINKS
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Index entries for sequences related to card matching
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FORMULA
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a(n)=3binomial(n, 3)*sum(binomial(n, k+3)*binomial(n, k)*binomial(n-3, k), k=0..n-3) +6n*binomial(n, 2)*sum(binomial(n, k+1)*binomial(n-1, k+2)*binomial(n-2, k), k=0..n-3)+n^3*sum(binomial(n-1, k)^3, k=0..n-1).
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CROSSREFS
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Cf. A000279, A000535.
Sequence in context: A143039 A111921 A118994 this_sequence A075852 A068792 A159646
Adjacent sequences: A000486 A000487 A000488 this_sequence A000490 A000491 A000492
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
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More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 26 2000
More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Feb 19 2004
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