A266922 - OEIS

A266922

Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, southwest or southeast neighbor modulo 3 and the upper left element equal to 0.

1, 4, 8, 22, 54, 142, 368, 974, 2596, 6978, 18956, 51750, 142624, 394594, 1099946, 3076470, 8654090, 24416490, 69188320, 196569386, 560336468, 1600901762, 4585812858, 13161785906, 37855003558, 109058776534, 314733656956

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Row 3 of A266921.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..132

EXAMPLE

Some solutions for n=7

..0..2..1..0..2..0..1....0..2..1..2..0..1..2....0..1..2..0..2..1..2

..0..1..0..2..1..2..1....0..1..0..1..2..0..1....2..0..1..2..1..0..1

..2..1..2..1..0..2..0....2..1..2..0..1..2..0....1..2..0..1..0..2..0