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A013520
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A problem in derangements.
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0
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0, 2, 9, 100, 1237, 18896, 337663, 6941194, 161357425, 4186540456, 119942830785, 3761004532550, 128121728853479, 4711881688294652, 186065500280409423, 7852240169544076190, 352684377274345906213, 16798134072300013751064
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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REFERENCES
| Frank Schmidt and Rodica Simion, Card shuffling and a transformation on S_n, Aequationes Math. 44 (1992), no. 1, 11-34.
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FORMULA
| The reference gives a generating function.
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MAPLE
| a := n->simplify((n-1)!*sum(n^k/k!, k=0..n-1)-2*(n-1)^(n-1)): b := simplify(x^2+sum(a(n)*x^n/n!, n=3..70)): f := simplify(exp(b)): fser := simplify(series(f, x=0, 27)): s := seq(simplify(n!*coeff(fser, x^n)), n=1..25);
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CROSSREFS
| Sequence in context: A013057 A027686 A187647 * A041239 A098610 A125815
Adjacent sequences: A013517 A013518 A013519 * A013521 A013522 A013523
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms and Maple code from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 09 2004
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