A266133 Number of 3Xn integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself.

1, 20, 77, 117, 278, 1959, 11044, 36730, 123887, 598383, 2919993, 11429093, 43919671, 194434626, 880889564, 3627851352, 14690154222, 63196827262, 276336307138, 1159331148853, 4807640087709, 20468995961561, 88006303609494

Offset: 1

Author

R. H. Hardin, Dec 21 2015

Keywords

• nonn

Comments

Row 3 of A266131.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210
• R. H. Hardin, Empirical recurrence of order 77

Crossrefs

Cf. A266131.

Formula

Empirical recurrence of order 77 (see link above)