id:A140662 - OEIS Search Results

Search: id:A140662

Displaying 1-1 of 1 results found.

page 1

Number of possible column states for self-avoiding polygons in a slit of width n.

+0
2

1, 3, 8, 20, 50, 126, 322, 834, 2187, 5797, 15510, 41834, 113633, 310571, 853466, 2356778, 6536381, 18199283, 50852018, 142547558, 400763222, 1129760414, 3192727796, 9043402500, 25669818475, 73007772801, 208023278208 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`Essentially equal to A001006(n+2)-1, n>1.`
	LINKS	`J. Alvarez, E.J. Janse van Rensburg et al Self-avoiding walks and polygons in slits.`
	FORMULA	`a(n)=sum_{m=1..[(n+1)/2]} (n+1)!/((n+1-2m)!m!(m+1)!).`
	CROSSREFS	`Cf. A055151, A080159, A088617, A107131, A097610.` `Sequence in context: A122595 A026582 A101893 this_sequence A077997 A027220 A026995` `Adjacent sequences: A140659 A140660 A140661 this_sequence A140663 A140664 A140665`
	KEYWORD	`easy,nonn`
	AUTHOR	`R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 11 2008`

page 1

Search completed in 0.002 seconds

Last modified December 20 00:58 EST 2009. Contains 171054 sequences.

AT&T Labs Research