A195213 Number of lower triangles of an n X n integer array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by 1 or less and triangles differing by a constant counted only once.

1, 7, 91, 2277, 111031, 10654607, 2021888119, 761408842173, 570411420721871, 851650667866314005, 2537743716708476573853, 15108768742290768272235707, 179885152873727967922701202921, 4286156683596201247493358770260469

Offset: 1

Author

R. H. Hardin Sep 13 2011

Keywords

• nonn

Comments

Column 1 of A195220

Examples

			Some solutions for n=5
...0...............0...............0...............0...............0
...1..0...........-1.-1...........-1..0...........-1..0............1..1
...0..0..1........-2.-2.-1........-1..0..1.........0..0.-1.........0..1..0
...0..1..1..1.....-1.-1.-1.-2......0..0..0..1......1..0.-1.-2......0..1..1..0
...1..0..1..0..0..-1.-1.-2.-1.-2...0..0..1..1..2...1..0.-1.-2.-1...0..0..1..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..16