A195226 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 2 of A195232

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..20

EXAMPLE

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