id:A144662 - OEIS Search Results

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a(n) = Sum_{i=1..n} Sum_{j=1..n} Sum_{k=1..n} Sum_{l=1..n} (i+j+k+l)!/(4!*i!*j!*k!*l!).

+0
4

0, 1, 266, 45296, 7958726, 1495388159, 295887993624, 60790021361170, 12845435390707724, 2774049143394729653, 609542744597785306189, 135840016223787254538508, 30629983532857972983331740, 6975352854342057056747327899, 1602003695575764851150428242804, 370631496919828403109950449644134 (list; graph; listen)

	OFFSET	`0,3`
	LINKS	`David Applegate and N. J. A. Sloane, The Gift Exchange Problem (arXiv:0907.0513, 2009)`
	MAPLE	`f:=n->add( add( add( add( (i+j+k+l)!/(4!i!j!k!l!), i=1..n), j=1..n), k=1..n), l=1..n); [seq(f(n), n=0..16)];`
	CROSSREFS	`Column 4 of A144512. Cf. A144660. A144661.` `Sequence in context: A061662 A028528 A028523 this_sequence A060402 A049014 A062037` `Adjacent sequences: A144659 A144660 A144661 this_sequence A144663 A144664 A144665`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Feb 01 2009`

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.

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