id:A032120 - OEIS Search Results

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Number of reversible strings with n beads of 3 colors.

+0
6

3, 6, 18, 45, 135, 378, 1134, 3321, 9963, 29646, 88938, 266085, 798255, 2392578, 7177734, 21526641, 64579923, 193720086, 581160258, 1743421725, 5230265175, 15690618378, 47071855134, 141215033961, 423645101883 (list; graph; listen)

	OFFSET	`1,1`
	LINKS	`C. G. Bower, Transforms (2)`
	FORMULA	`"BIK" (reversible, indistinct, unlabeled) transform of 3, 0, 0, 0...` `(1/2){(2-(-1)^n)3^[n/2] + 3^n}. - R. Stephan, May 11 2004`
	CROSSREFS	`Equals 3 * A001444.` `Sequence in context: A007990 A121188 A120718 this_sequence A115344 A151262 A148555` `Adjacent sequences: A032117 A032118 A032119 this_sequence A032121 A032122 A032123`
	KEYWORD	`nonn`
	AUTHOR	`Christian G. Bower (bowerc(AT)usa.net)`

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Last modified November 24 14:25 EST 2009. Contains 167438 sequences.

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