A195226 Number of lower triangles of an n X n 0..2 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.
3, 15, 155, 3151, 127785, 10322065, 1663418313, 535153390177, 343932423395227, 441776066934784687, 1134608168927438377475, 5828490619001307113164495, 59904949456032239303490933489, 1232191818850202836476827846621041
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2........1........1........1........2........2........0........2 ..1.1......1.2......1.1......1.2......1.1......1.1......0.0......1.1 ..0.1.1....1.1.2....1.1.1....1.2.2....1.1.0....0.1.1....1.0.1....0.0.0 ..0.1.1.0..1.1.1.2..0.1.0.0..1.1.2.2..1.1.0.0..0.0.1.1..1.0.0.0..1.1.0.0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..20
Comments