A194927 Number of lower triangles of an n X n 0..4 array with no element differing from any of its horizontal or vertical neighbors by more than one

5, 35, 557, 19379, 1481501, 248381815, 91397735301, 73818960495633, 130889487125186283, 509545270244514585603, 4355460540545035980173055, 81748120032524783307283152379, 3369206664229541719414619846139771

Offset

1,1

Comments

Column 4 of A194931

Links

R. H. Hardin, Table of n, a(n) for n = 1..15

Example

Some solutions for 4X4
..3........1........1........3........2........3........3........4
..3.2......2.3......2.2......3.2......2.1......2.1......3.3......3.4
..2.1.2....2.3.3....3.3.2....4.3.3....1.1.2....3.2.1....4.4.3....2.3.2
..2.2.1.2..3.2.3.4..2.2.2.3..4.3.3.3..2.2.3.2..2.1.2.2..4.3.4.3..1.2.1.2

Crossrefs

Sequence in context: A034217 A011556 A361055 * A089043 A317995 A260075

Adjacent sequences: A194924 A194925 A194926 * A194928 A194929 A194930

Keyword

nonn

Author

R. H. Hardin Sep 05 2011

Status

approved