A079189 - OEIS

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A079189

Number of anti-commutative closed binary operations (groupoids) on a set of order n.

1, 8, 5832, 764411904, 32000000000000000, 669462604992000000000000000, 10090701947420325348336258984797490118656, 181258495964203522486308107281962138904949048737792 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`A079176(n)+A079179(n)=A002489(n).` `Each a(n) is equal to the sum of the products of each element in row n of A079191 and the corresponding element of A079210.`
	LINKS	`C. van den Bosch, Closed binary operations on small sets` `Index entries for sequences related to groupoids`
	FORMULA	`(n^n)((n^2-n)^((n^2-n)/2))`
	CROSSREFS	`Cf. A079186, A079190, A079191. a(n)=A023813(n)A023813(n-1).` `Sequence in context: A062030 A052497 A179151 A114133 A173190 A115442` `Adjacent sequences: A079186 A079187 A079188 * A079190 A079191 A079192`
	KEYWORD	`nonn`
	AUTHOR	`Christian van den Bosch (cjb(AT)cjb.ie), Jan 03 2003`
	EXTENSIONS	`Edited and extended by Christian G. Bower (bowerc(AT)usa.net), Dec 12 2003`

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Last modified February 17 19:13 EST 2012. Contains 206085 sequences.