id:A128598 - OEIS Search Results

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Column 3 of triangle A128596; a(n) = coefficient of q^(3n+9) in the q-analog of the even double factorials (2n+6)!! for n>=0.

+0
3

1, 24, 297, 3210, 32510, 318171, 3054100, 28980565, 273077443, 2562036673, 23973009386, 223949654108, 2090070431683, 19496003736658, 181815760387221, 1695523268254637, 15813185728272754, 147508341317700463 (list; graph; listen)

	OFFSET	`0,2`
	FORMULA	`a(n) = [q^(3n+9)] Product_{j=1..n+3} (1-q^(2j))/(1-q) for n>=0.`
	PROGRAM	`(PARI) {a(n)=polcoeff(prod(j=1, n+3, (1-q^(2j))/(1-q)), 3n+9, q)}`
	CROSSREFS	`Cf. A128596; A128084; A000165 ((2n)!!); A128086 (column 1), A128597 (column 2).` `Sequence in context: A035475 A042110 A086941 this_sequence A153782 A073990 A056290` `Adjacent sequences: A128595 A128596 A128597 this_sequence A128599 A128600 A128601`
	KEYWORD	`nonn`
	AUTHOR	`Paul D. Hanna (pauldhanna(AT)juno.com), Mar 12 2007`

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Last modified December 10 12:37 EST 2009. Contains 170569 sequences.

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