id:A098992 - OEIS Search Results

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Number of permutations of [n] with exactly 2 descents which avoid the pattern 1324.

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1

0, 0, 1, 11, 55, 190, 526, 1254, 2682, 5280, 9735, 17017, 28457, 45838, 71500, 108460, 160548, 232560, 330429, 461415, 634315, 859694, 1150138, 1520530, 1988350, 2574000, 3301155, 4197141, 5293341, 6625630, 8234840, 10167256, 12475144 (list; graph; listen)

	OFFSET	`1,4`
	FORMULA	`G.f.: q^3(1+3q-5q^2+2q^3)/(1-q)^8`
	CROSSREFS	`Cf. A061552, A000292.` `Sequence in context: A009550 A022606 A072025 this_sequence A156589 A165791 A032166` `Adjacent sequences: A098989 A098990 A098991 this_sequence A098993 A098994 A098995`
	KEYWORD	`easy,nonn`
	AUTHOR	`Mike Zabrocki (zabrocki(AT)mathstat.yorku.ca), Nov 05 2004`

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

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