id:A108411 - OEIS Search Results

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3^[n/2]. Powers of 3 repeated.

+0
6

1, 1, 3, 3, 9, 9, 27, 27, 81, 81, 243, 243, 729, 729, 2187, 2187, 6561, 6561, 19683, 19683, 59049, 59049, 177147, 177147, 531441, 531441, 1594323, 1594323, 4782969, 4782969, 14348907, 14348907, 43046721, 43046721, 129140163 (list; graph; listen)

	OFFSET	`0,3`
	COMMENT	`a(n) is the Parker sequence for the automorphism group of the limit of the class of oriented graphs; a(n) counts the finite circulant structures in that class. - Nour-Eddine Fahssi (fahssin(AT)yahoo.fr), Feb 18 2008`
	LINKS	`D. A. Gewurz and F. Merola, Sequences realized as Parker vectors of oligomorphic permutation groups, J. Integer Seq., 6 (2003), 03.1.6.`
	FORMULA	`O.g.f.: -(1+x)/(-1+3*x^2). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 01 2008`
	CROSSREFS	`Essentially the same as A056449. Cf. A000244, A016116.` `Sequence in context: A145957 A056449 A128019 this_sequence A146788 A147244 A146575` `Adjacent sequences: A108408 A108409 A108410 this_sequence A108412 A108413 A108414`
	KEYWORD	`nonn`
	AUTHOR	`Ralf Stephan, Jun 05 2005`

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Last modified November 21 14:49 EST 2008. Contains 150807 sequences.

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