A089847 - OEIS

This site is supported by donations to The OEIS Foundation.

A089847

Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A089851/A089853.

1, 1, 2, 3, 8, 24, 72, 231, 764, 2574, 8840, 30796, 108528, 386308, 1386756, 5014575, 18249120, 66786738, 245642760, 907513530, 3366215688, 12531502620, 46805032560, 175341580596, 658674458208, 2480584898700, 9363748625972 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	COMMENTS	`The number of orbits to which the corresponding automorphism(s) partitions the set of A000108(n) binary trees with n internal nodes.`
	LINKS	`A. Karttunen, C-program for computing the initial terms of this sequence`
	FORMULA	`a(n) = (1/3 * A000108(n)) + (2/3 * A089848(n))`
	MAPLE	`A089847 := n -> (1/3)(A000108(n)+2A089848(n));`
	PROG	`(Scheme) (define (A089847 n) (/ (+ (A000108 n) (* 2 (A089848 n))) 3))`
	CROSSREFS	`Sequence in context: A032096 A120763 A120708 * A038561 A055981 A120260` `Adjacent sequences: A089844 A089845 A089846 * A089848 A089849 A089850`
	KEYWORD	`nonn,easy`
	AUTHOR	`Antti Karttunen (His_Firstname.His_Surname(AT)iki.fi), Nov 29 2003`

Content is available under The OEIS End-User License Agreement .

Last modified February 15 19:07 EST 2012. Contains 205852 sequences.