id:A100312 - OEIS Search Results

Search: id:A100312

Displaying 1-1 of 1 results found.

page 1

Number of 3 X n binary matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (10;0) and (01;1). An occurrence of a ranpp (xy;z) in a matrix A=(a(i,j)) is a triple (a(i1,j1), a(i1,j2), a(i2,j1)) where i1<i2, j1<j2 and these elements are in the same relative order as those in the triple (x,y,z). In general, the number of m X n 0-1 matrices in question is given by the g.f. 2xy/(1-2(x+y-xy)).

+0
2

8, 32, 104, 304, 832, 2176, 5504, 13568, 32768, 77824, 182272, 421888, 966656, 2195456, 4947968, 11075584, 24641536, 54525952, 120061952, 263192576, 574619648, 1249902592, 2709520384, 5855248384 (list; graph; listen)

	OFFSET	`1,1`
	LINKS	`S. Kitaev, On multi-avoidance of right angled numbered polyomino patterns, Integers: Electronic Journal of Combinatorial Number Theory 4 (2004), A21, 20pp.`
	FORMULA	`G.f.: 8x(1-x)^2/(1-2x)^3` `(n^2 + 5n + 2) 2^(n-1).`
	CROSSREFS	`Equals 8 * A049611(n).` `Cf. m=4: A100313.` `Sequence in context: A014969 A139820 A071345 this_sequence A003201 A036393 A081654` `Adjacent sequences: A100309 A100310 A100311 this_sequence A100313 A100314 A100315`
	KEYWORD	`nonn`
	AUTHOR	`Sergey Kitaev (kitaev(AT)ms.uky.edu), Nov 13 2004`

page 1

Search completed in 0.002 seconds

Last modified December 7 08:40 EST 2009. Contains 170430 sequences.

AT&T Labs Research