A195253 Number of lower triangles of a 7X7 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by two or less.

268435456, 22876792454961, 254948725307650, 786909681200387, 1479091549959182, 2226347741716207, 2987571816007840, 3751562406061261, 4515974674903982, 5280435818615649, 6044900876514412, 6809366105107111

Offset: 1

Author

R. H. Hardin Sep 13 2011

Keywords

• nonn

Comments

Row 7 of A195248

Examples

			Some solutions for n=5
..3..............2..............5..............0..............5
..4.5............3.4............4.3............2.0............3.3
..4.4.3..........5.4.5..........2.4.4..........0.2.0..........2.2.4
..2.3.2.4........5.5.4.4........3.3.2.4........2.2.2.0........1.2.3.2
..3.3.3.3.4......3.4.4.2.3......3.4.3.4.3......2.1.0.1.1......0.2.4.4.2
..3.3.1.2.4.4....2.4.3.2.2.1....3.4.5.3.2.2....0.1.2.1.1.2....0.2.3.3.4.4
..3.2.2.3.4.5.4..2.2.2.2.3.1.1..3.3.3.3.2.1.1..1.2.3.2.0.1.0..2.2.1.3.3.5.3
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 764465228592699*n - 2364216638005277 for n>10