id:A116734 - OEIS Search Results

Search: id:A116734

Displaying 1-1 of 1 results found.

page 1

Number of permutations of length n which avoid the patterns 231, 1432, 4123.

+0
1

1, 2, 5, 12, 25, 50, 97, 184, 345, 642, 1189, 2196, 4049, 7458, 13729, 25264, 46481, 85506, 157285, 289308, 532137, 978770, 1800257, 3311208, 6090281, 11201794, 20603333, 37895460, 69700641, 128199490, 235795649, 433695840, 797691041 (list; graph; listen)

	OFFSET	`1,2`
	LINKS	`Lara Pudwell, Systematic Studies in Pattern Avoidance, 2005.`
	FORMULA	`G.f.: A(x) = -{x(x^2+x^3+1-x)}/{(x-1)^2(x^3+x^2+x-1)}` `a(n)=A000213(n+2)-n-1. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 05 2008]`
	CROSSREFS	`Sequence in context: A116722 A116730 A067331 this_sequence A101836 A122439 A063807` `Adjacent sequences: A116731 A116732 A116733 this_sequence A116735 A116736 A116737`
	KEYWORD	`nonn,easy`
	AUTHOR	`Lara Pudwell (Lara.Pudwell(AT)valpo.edu), Feb 26 2006`
	EXTENSIONS	`Extended beyond a(30) by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 05 2008`

page 1

Search completed in 0.002 seconds

Last modified November 18 20:14 EST 2008. Contains 147244 sequences.

AT&T Labs Research