A078603 - OEIS

This site is supported by donations to The OEIS Foundation.

A078603

Number of ways of arranging the numbers 1..n in a circle so that adjacent numbers do not differ by 1 mod n.

1, 0, 0, 0, 2, 6, 46, 354, 3106, 29926, 315862, 3628906, 45132474, 604534846, 8680957902, 133082437730, 2169964347282, 37505486702678, 685046187718022, 13186335387855770, 266816610979894058, 5662225862272325550 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,5`
	LINKS	`Index entries for sequences related to shoe lacings`
	FORMULA	`See A002816.`
	EXAMPLE	`a(5) = 2: 1 3 5 2 4, 1 4 2 5 3; a(6) = 6: 1 4 6 2 5 3, 1 5 2 4 6 3, 1 5 3 6 2 4, 1 3 6 4 2 5, 1 4 2 6 3 5, 1 3 5 2 6 4.`
	CROSSREFS	`Twice A002816. The sequence na(n) is A089222. See also A078628.` `Sequence in context: A136557 A092662 A052811 A001587 A078537 A145502` `Adjacent sequences: A078600 A078601 A078602 * A078604 A078605 A078606`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Dec 11 2002`
	EXTENSIONS	`The sequence was missing a zero; also added a cross-reference Joel Brewster Lewis (jblewis(AT)post.harvard.edu), Jan 28 2010`

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

Last modified February 16 14:37 EST 2012. Contains 205930 sequences.