login
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
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
OFFSET
1,2
COMMENTS
Row 3 of A266921.
LINKS
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
CROSSREFS
Cf. A266921.
Sequence in context: A058855 A297339 A290138 * A284778 A057583 A129788
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2016
STATUS
approved