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A194889
Number of lower triangles of an n X n 0..4 array with new values introduced in row major order 0..4 and no two horizontal or vertical neighbors of any element equal
0
1, 3, 33, 1620, 136080, 17962560, 3751608960, 1233597237120, 641473938397440, 526921921428975360
OFFSET
1,2
COMMENTS
Column 4 of A194893
EXAMPLE
Some solutions for 4X4
..0........0........0........0........0........0........0........0
..1.2......0.1......1.2......1.1......0.1......1.2......0.1......1.1
..3.0.1....2.3.4....1.3.0....2.3.4....2.1.3....1.2.3....2.1.0....2.3.3
..4.0.3.2..2.0.1.1..0.4.2.1..2.0.1.1..2.0.4.4..4.0.1.4..2.3.0.1..2.0.4.2
CROSSREFS
Sequence in context: A113111 A118188 A342170 * A126675 A038694 A319750
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 04 2011
STATUS
approved