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Search: id:A001052
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| A001052 |
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a(n) = n(n-1)a(n-1)/2 + a(n-2).
(Formerly M0911 N0343)
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+0
2
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| 1, 2, 3, 11, 69, 701, 10584, 222965, 6253604, 225352709, 10147125509, 558317255704, 36859086001973, 2875567025409598, 261713458398275391, 27482788698844325653, 3298196357319717353751, 448582187384180404435789
(list; graph; listen)
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OFFSET
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0,2
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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).
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PROGRAM
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(PARI) a(n)=if(n<2, max(0, n+1), n*(n-1)*a(n-1)/2+a(n-2))
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CROSSREFS
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Adjacent sequences: A001049 A001050 A001051 this_sequence A001053 A001054 A001055
Sequence in context: A105217 A066046 A065597 this_sequence A155187 A109132 A008510
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KEYWORD
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nonn,easy
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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 James A. Sellers (sellersj(AT)math.psu.edu), Sep 19 2000
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