A271029 Number of nXnXn triangular 0..3 arrays with some element less than a w, nw or ne neighbor exactly once.

0, 20, 294, 3114, 29120, 256020, 2173554, 18060096, 147976270, 1201034302, 9684108034, 77719446198, 621623562780, 4959585660212, 39496945637162, 314112558505488, 2495519478658458, 19810840820555514, 157179628657888198

Offset: 1

Author

R. H. Hardin, Mar 29 2016

Keywords

• nonn

Comments

Column 3 of A271034.

Examples

			Some solutions for n=4
.....3........0........0........1........1........0........0........0
....0.3......0.2......0.0......1.1......1.1......0.2......0.2......1.0
...0.3.3....1.3.3....0.0.1....1.3.2....0.2.2....0.2.2....1.2.2....1.3.3
..0.3.3.3..1.2.3.3..2.1.1.3..1.3.3.3..1.2.2.3..1.1.2.3..2.3.2.2..3.3.3.3
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..20

Crossrefs

Cf. A271034.