id:A080500 - OEIS Search Results

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a(n) = (n-1)(n-4)(n-9)...(n-k^2) where k^2 < n <= (k+1)^2.

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1, 1, 2, 3, 4, 10, 18, 28, 40, 54, 140, 264, 432, 650, 924, 1260, 1664, 4284, 8100, 13376, 20400, 29484, 40964, 55200, 72576, 93500, 236808, 443232, 728000, 1108380, 1603800, 2235968, 3028992, 4009500, 5206760, 6652800, 8382528, 20867704 (list; graph; listen)

	OFFSET	`1,3`
	COMMENT	`The idea of A080497 to A080500 when applied to Euler's phi function i.e. on phi-torial function defined in A001783 yields A001783 itself for obvious reasons. Is there any other such example?`
	EXAMPLE	`a(6) = (6-1)(6-4)= 10.`
	CROSSREFS	`Cf. A080497, A080498, A072513.` `Sequence in context: A056701 A055506 A098088 this_sequence A007661 A049891 A135432` `Adjacent sequences: A080497 A080498 A080499 this_sequence A080501 A080502 A080503`
	KEYWORD	`nonn`
	AUTHOR	`Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 19 2003`
	EXTENSIONS	`More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003`

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Last modified December 7 08:40 EST 2009. Contains 170430 sequences.

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