id:A109414 - OEIS Search Results

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a(n) equals the (n*(n+1)/2)-th partial sum of the self-convolution cube of A010054, which has the g.f.: Sum_{k>=0} x^(k*(k+1)/2).

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1, 4, 11, 26, 54, 90, 151, 232, 326, 456, 612, 811, 1030, 1304, 1607, 1953, 2383, 2812, 3329, 3893, 4515, 5226, 5983, 6809, 7703, 8718, 9762, 10891, 12160, 13475, 14868, 16380, 17986, 19699, 21524, 23415, 25482, 27658, 29923, 32288, 34814, 37452 (list; graph; listen)

	OFFSET	`0,2`
	FORMULA	`a(n) = [x^(n(n+1)/2)] [Sum_{k>=0} x^(k(k+1)/2)]^3/(1-x).`
	PROGRAM	`(PARI) {a(n)=local(X=x+xO(x^(n(n+1)/2))); polcoeff((eta(X^2)^2/eta(X))^3/(1-X), n*(n+1)/2)}`
	CROSSREFS	`Cf. A109413, A109415, A010054.` `Sequence in context: A002763 A077270 A076048 this_sequence A027966 A027660 A002940` `Adjacent sequences: A109411 A109412 A109413 this_sequence A109415 A109416 A109417`
	KEYWORD	`nonn`
	AUTHOR	`Paul D. Hanna (pauldhanna(AT)juno.com), Jun 27 2005`

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Last modified July 26 23:19 EDT 2008. Contains 142293 sequences.

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