id:A089407 - OEIS Search Results

Search: id:A089407

Displaying 1-1 of 1 results found.

page 1

Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A089859/A089863.

+0
3

1, 1, 1, 2, 4, 11, 34, 109, 360, 1219, 4206, 14708, 52024, 185758, 668676, 2423821, 8839632, 32411555, 119410390, 441817020, 1641032536, 6116570954, 22870649308, 85764918130, 322476066224, 1215486652366, 4591838372044, 17383387914792 (list; graph; listen)

	OFFSET	`0,4`
	COMMENT	`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(0) = a(1) = 1, a(n) = (1/4)(A000108(n) + A089408(n) + (if (n == 3 mod 4) 2A000108((n-3)/4)))`
	PROGRAM	`(Scheme) (define (A089407 n) (if (< n 2) 1 (* (/ 1 4) (+ (A000108 n) (A089408 n) (if (= 3 (modulo n 4)) (* 2 (A000108 (/ (- n 3) 4))) 0)))))`
	CROSSREFS	`Adjacent sequences: A089404 A089405 A089406 this_sequence A089408 A089409 A089410` `Sequence in context: A076316 A082104 A099215 this_sequence A071115 A076317 A076318`
	KEYWORD	`nonn,easy`
	AUTHOR	`Antti Karttunen (His_Firstname.His_Surname(AT)iki.fi), Nov 29 2003`

page 1

Search completed in 0.002 seconds

Last modified October 7 14:39 EDT 2008. Contains 144666 sequences.

AT&T Labs Research