A195243 Number of lower triangles of an n X n 0..3 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by two or less.

4, 46, 1682, 190514, 67379894, 74236765958, 254948725307650, 2728873272983950594, 91038149737139587502854, 9466106148769015848820814134, 3067809430979519600024270636572850

Offset: 1

Author

R. H. Hardin Sep 13 2011

Keywords

• nonn

Comments

Column 3 of A195248

Examples

			Some solutions for n=5
..1..........2..........1..........3..........0..........1..........0
..0.2........2.1........0.2........1.1........2.1........1.3........2.1
..2.0.2......2.0.0......2.1.3......1.1.2......0.2.2......3.3.1......0.2.2
..0.0.1.3....2.1.1.2....0.2.1.3....3.2.1.1....2.1.1.0....3.1.1.3....2.1.1.0
..0.1.2.3.3..1.2.2.1.0..2.1.3.3.3..2.1.2.2.3..1.0.0.1.2..2.3.2.2.1..1.0.0.1.2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..18