A266682 Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its northwest or northeast neighbor modulo 3 and the upper left element equal to 0.

2, 5, 15, 59, 257, 1205, 5879, 29693, 153097, 806375, 4307317, 23313947, 127420533, 702562447, 3900415155, 21786817517, 122309555899, 689707853981, 3904123962093, 22174631940293, 126322762595339, 721552901977497

Offset: 1

Author

R. H. Hardin, Jan 02 2016

Keywords

• nonn

Comments

Row 3 of A266681.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..72

Crossrefs

Cf. A266681.