A267023 Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to or 1 greater than any northeast or northwest neighbors modulo 4 and the upper left element equal to 0.

6, 8, 21, 137, 759, 4835, 31591, 216460, 1516047, 10864196, 79437844, 590119523, 4453596825, 34028591249, 263304258843, 2058154419091, 16252842542358, 129434331448080, 1039407597863960, 8405943746368118, 68447035142972923

Offset: 1

Author

R. H. Hardin, Jan 09 2016

Keywords

• nonn

Comments

Row 4 of A267019.

Examples

			Some solutions for n=4
..0..1..3..1....0..2..0..2....0..2..0..2....0..2..0..2....0..1..3..1
..2..0..2..0....3..1..3..1....2..0..3..1....3..1..3..1....2..0..2..0
..1..3..1..3....1..0..2..3....1..3..1..3....1..3..1..3....0..2..1..3
..0..2..3..2....1..2..0..3....0..1..3..2....0..2..0..2....3..1..3..2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..23

Crossrefs

Cf. A267019.