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A002220
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a(n) is the number of partitions of 3n that can be obtained by adding together three (not necessarily distinct) partitions of n.
(Formerly M3395 N1374)
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5
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1, 4, 10, 30, 65, 173, 343, 778, 1518, 3088, 5609, 10959, 18990, 34441, 58903, 102044, 167499, 282519, 451529, 737208, 1160102, 1836910, 2828466, 4410990, 6670202, 10161240, 15186315, 22758131, 33480869
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OFFSET
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1,2
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REFERENCES
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N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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Table of n, a(n) for n=1..29.
N. Metropolis and P. R. Stein, An elementary solution to a problem in restricted partitions, J. Combin. Theory, 9 (1970), 365-376.
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CROSSREFS
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See A002219 for further details. Cf. A002221, A002222, A213074.
A column of A213086.
Sequence in context: A330529 A048044 A047188 * A222807 A090578 A007713
Adjacent sequences: A002217 A002218 A002219 * A002221 A002222 A002223
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane
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EXTENSIONS
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Edited by N. J. A. Sloane, Jun 03 2012
a(12)-a(20) from Alois P. Heinz, Jul 10 2012
a(21)-a(29) from Sean A. Irvine, Sep 05 2013
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STATUS
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approved
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