A266494 Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, west, northwest or northeast neighbor modulo 3 and the upper left element equal to 0.

1, 1, 1, 1, 1, 4, 13, 43, 126, 324, 778, 1793, 3987, 8829, 19834, 45595, 108018, 262830, 649760, 1616712, 4017230, 9918783, 24298995, 59106475, 143053466, 345488182, 834978806, 2023884376, 4926308771, 12044390596, 29559301171, 72735281708

Offset

1,6

Comments

Row 3 of A266493.

Links

R. H. Hardin, Table of n, a(n) for n = 1..106

Example

Some solutions for n=7 ..0..0..2..2..1..1..1....0..0..2..2..1..1..1....0..0..2..2..1..1..0 ..0..2..2..1..1..0..0....2..2..2..1..1..0..0....2..2..2..1..1..0..0 ..2..2..1..1..0..0..2....2..2..1..1..0..0..0....2..1..1..1..0..0..2

Crossrefs

Cf. A266493.

Sequence in context: A047144 A072307 A355116 * A121486 A339063 A188176

Adjacent sequences: A266491 A266492 A266493 * A266495 A266496 A266497

Keyword

nonn

Author

R. H. Hardin, Dec 30 2015

Status

approved