A266600 Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north or northeast neighbor modulo 3 and the upper left element equal to 0.

1, 2, 6, 20, 83, 410, 2109, 11097, 59698, 325240, 1786820, 9888567, 55061514, 308166631, 1732444205, 9777801332, 55377818912, 314616215640, 1792424007975, 10237590562396, 58607205582421, 336211631539125, 1932440491804486

Offset

1,2

Comments

Row 3 of A266599.

Links

R. H. Hardin, Table of n, a(n) for n = 1..102

Example

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

Crossrefs

Cf. A266599.

Sequence in context: A337274 A115084 A177476 * A177474 A372987 A177480

Adjacent sequences: A266597 A266598 A266599 * A266601 A266602 A266603

Keyword

nonn

Author

R. H. Hardin, Jan 01 2016

Status

approved