A194926 Number of lower triangles of an n X n 0..3 array with no element differing from any of its horizontal or vertical neighbors by more than one

4, 26, 386, 12474, 882318, 136403494, 46128809462, 34125388757746, 55232992212354490, 195592244264620494970, 1515477849222357994524778, 25692027725435091847764127738, 953019093594286117476472624693750

Offset

1,1

Comments

Column 3 of A194931

Links

R. H. Hardin, Table of n, a(n) for n = 1..16

Example

Some solutions for 4X4
..1........2........0........2........1........3........0........0
..2.1......2.3......0.0......2.3......2.1......2.3......1.1......1.0
..2.1.1....1.2.2....1.1.1....3.2.2....1.2.3....2.2.1....1.0.1....2.1.0
..1.1.2.2..2.2.2.1..2.2.2.2..2.3.2.3..2.3.3.3..2.2.1.2..2.1.2.3..2.1.0.1

Crossrefs

Sequence in context: A348117 A317668 A328419 * A167147 A322395 A326264

Adjacent sequences: A194923 A194924 A194925 * A194927 A194928 A194929

Keyword

nonn

Author

R. H. Hardin Sep 05 2011

Status

approved