A266862 Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north or southwest neighbor modulo 3 and the upper left element equal to 0.

1, 4, 17, 66, 324, 1565, 7908, 41440, 219394, 1181538, 6433652, 35322999, 195435804, 1087909500, 6087937840, 34225256140, 193178201178, 1094225487556, 6217602330366, 35429358636014, 202398423255902, 1158911705466210

Offset

1,2

Comments

Row 3 of A266861.

Links

R. H. Hardin, Table of n, a(n) for n = 1..105

Example

Some solutions for n=4
..0..2..1..1....0..2..1..0....0..2..0..1....0..1..0..2....0..1..1..2
..0..2..1..0....2..1..1..0....2..1..2..0....2..1..0..2....2..1..0..2
..0..2..1..2....2..1..0..2....1..0..1..2....2..1..0..1....2..0..0..1

Crossrefs

Cf. A266861.

Sequence in context: A291394 A244616 A030529 * A239845 A081113 A368429

Adjacent sequences: A266859 A266860 A266861 * A266863 A266864 A266865

Keyword

nonn

Author

R. H. Hardin, Jan 04 2016

Status

approved