id:A113583 - OEIS Search Results

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Number of permutations of length 2n-1 with no local maxima in even positions.

+0
2

1, 4, 56, 1632, 81664, 6241280, 676506624, 98709925888, 18655203885056, 4432984678858752, 1293646660855398400, 454816628946740707328, 189608469405709753122816, 92483656403812275277791232, 52178449263441077156062429184, 33716638014695384983287984291840, 24738782851403087736929931445141504 (list; graph; listen)

	OFFSET	`1,2`
	REFERENCES	`M. La Croix, A combinatorial proof of a result of Gessel and Greene, Discr. Math., 306 (2006), 2251-2256.`
	FORMULA	`Sum_{n>=1} a_n x^(2n-1)/(2n-1)! = tanh(x)/(1-x tanh(x)).`
	CROSSREFS	`Cf. A122647.` `Adjacent sequences: A113580 A113581 A113582 this_sequence A113584 A113585 A113586` `Sequence in context: A061924 A009536 A009558 this_sequence A009563 A111849 A009159`
	KEYWORD	`nonn`
	AUTHOR	`njas, Sep 21 2006`

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Last modified October 15 09:18 EDT 2008. Contains 145015 sequences.

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