A195227 Number of lower triangles of an n X n 0..3 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.

4, 22, 246, 5428, 237818, 20729610, 3601738548, 1249159521262, 865793424024974, 1200356073563114252, 3331551471246807302142, 18523112376180844925948966, 206425939461681776649215679048, 4613382950875473008207859661034814

Offset

1,1

Comments

Column 3 of A195232

Links

R. H. Hardin, Table of n, a(n) for n = 1..18

Example

Some solutions for n=4
..3........2........0........2........1........2........1........1
..3.2......3.2......1.1......1.2......1.0......2.3......1.0......0.1
..2.2.2....3.2.1....1.2.1....1.1.2....1.0.1....3.3.3....0.0.1....1.0.0
..3.2.3.3..2.2.2.1..2.2.2.1..1.2.1.1..1.0.1.2..3.3.2.3..1.0.1.0..1.0.0.1

Crossrefs

Sequence in context: A025135 A125801 A341459 * A265908 A359111 A119009

Adjacent sequences: A195224 A195225 A195226 * A195228 A195229 A195230

Keyword

nonn

Author

R. H. Hardin, Sep 13 2011

Status

approved