A266573 Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its northwest or southwest neighbor modulo 3 and the upper left element equal to 0.

2, 5, 15, 109, 574, 2840, 13767, 71646, 390862, 2170370, 11989812, 66094738, 366119221, 2044786962, 11503587136, 65003352026, 368281990242, 2091514533360, 11909843102866, 68009104297282, 389348569168108, 2233795881384252

Offset

1,1

Comments

Row 3 of A266572.

Links

R. H. Hardin, Table of n, a(n) for n = 1..73

Example

Some solutions for n=6
..0..1..1..0..0..1....0..2..0..1..1..0....0..2..2..0..1..2....0..1..0..0..1..1
..2..2..0..1..2..0....2..0..1..2..0..1....2..0..1..2..0..1....2..0..0..2..2..0
..2..1..2..0..1..2....0..1..2..1..2..2....1..1..0..1..2..0....1..1..2..2..1..2

Crossrefs

Cf. A266572.

Sequence in context: A032267 A191477 A196196 * A268121 A306794 A111790

Adjacent sequences: A266570 A266571 A266572 * A266574 A266575 A266576

Keyword

nonn

Author

R. H. Hardin, Jan 01 2016

Status

approved