A194790 Number of lower triangles of an (n+1)X(n+1) 0..4 array with new values introduced in row major order 0..4 and no element equal to any horizontal, diagonal, antidiagonal or vertical neighbor

1, 9, 252, 11160, 779544, 86082552, 15042748752, 4162973481720, 1825584767007624, 1269014066306135784, 1398647178389920392360, 2444528051373276536144472, 6776054483832917004333974184

Offset

1,2

Comments

Column 4 of A194794

Links

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

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......1.2......1.2
..3.0.4....0.3.1....3.0.3....3.4.1....0.3.1....3.4.0....3.0.4....0.3.1
..4.1.2.1..1.4.2.0..4.1.2.0..1.2.0.2..4.2.0.4..2.1.3.2..4.2.3.0..2.4.0.4

Crossrefs

Sequence in context: A135099 A073427 A303050 * A370357 A158621 A256019

Adjacent sequences: A194787 A194788 A194789 * A194791 A194792 A194793

Keyword

nonn

Author

R. H. Hardin Sep 03 2011

Status

approved