A266096 Number of n X 3 integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.

4, 13, 64, 230, 1012, 3928, 16428, 65736, 269908, 1091720, 4454304, 18082796, 73622676, 299247292, 1217498296, 4950677020, 20137255328, 81894658192, 333086633092, 1354665687204, 5509630157292, 22408041160240, 91136102570276

Offset: 1

Author

R. H. Hardin, Dec 21 2015

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 3 of A266101.

Formula

Empirical: a(n) = a(n-1) + 12*a(n-2) + 5*a(n-3) - 12*a(n-4) - 2*a(n-5).

Empirical g.f.: x*(4 + 9*x + 3*x^2 - 10*x^3 - 3*x^4) / (1 - x - 12*x^2 - 5*x^3 + 12*x^4 + 2*x^5). - Colin Barker, Jan 09 2019