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

1,1

Comments

Row 7 of A195248

Links

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

Formula

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

Example

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

Crossrefs

Sequence in context: A223698 A195237 A194936 * A122969 A137492 A105014

Adjacent sequences: A195250 A195251 A195252 * A195254 A195255 A195256

Keyword

nonn

Author

R. H. Hardin Sep 13 2011

Status

approved