

A013520


A problem in derangements.


0



0, 2, 9, 100, 1237, 18896, 337663, 6941194, 161357425, 4186540456, 119942830785, 3761004532550, 128121728853479, 4711881688294652, 186065500280409423, 7852240169544076190, 352684377274345906213, 16798134072300013751064
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OFFSET

0,2


LINKS

Table of n, a(n) for n=0..17.
Frank Schmidt and Rodica Simion, Card shuffling and a transformation on S_n, Aequationes Math. 44 (1992), no. 1, 1134.


FORMULA

The reference gives a generating function.


MAPLE

a := n>simplify((n1)!*sum(n^k/k!, k=0..n1)2*(n1)^(n1)): 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); # Emeric Deutsch, Mar 09 2004


CROSSREFS

Sequence in context: A187647 A322645 A277180 * A041239 A098610 A226391
Adjacent sequences: A013517 A013518 A013519 * A013521 A013522 A013523


KEYWORD

nonn


AUTHOR

N. J. A. Sloane


EXTENSIONS

More terms from Emeric Deutsch, Mar 09 2004


STATUS

approved



