A194892 Number of lower triangles of an n X n 0..7 array with new values introduced in row major order 0..7 and no two horizontal or vertical neighbors of any element equal

1, 3, 34, 5556, 15005952, 282616583760, 24289270603904160

Offset

1,2

Comments

Column 7 of A194893

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for 4X4
..0........0........0........0........0........0........0........0
..1.2......1.2......1.2......1.2......1.2......1.2......0.1......1.2
..3.4.5....3.4.4....3.0.1....3.3.0....3.3.4....3.2.0....2.3.4....3.3.4
..2.4.6.7..0.0.1.1..4.5.2.0..2.4.4.2..4.5.1.3..3.4.0.3..1.5.5.0..5.0.1.3

Crossrefs

Sequence in context: A194890 A197434 A194891 * A182382 A222787 A180126

Adjacent sequences: A194889 A194890 A194891 * A194893 A194894 A194895

Keyword

nonn

Author

R. H. Hardin Sep 04 2011

Status

approved