A195950 Number of lower triangles of an n X n 0..3 array with no element greater than the number its nonzero horizontal and vertical neighbors

1, 5, 162, 17424, 6756437, 9790899054, 53438526965463, 1095434478598715742, 84189100478450762470628, 24264818647445156524051251366, 26234269948355443957604222160170467

Offset

1,2

Links

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

Example

Some solutions for n=4
..1........1........1........0........1........1........0........0
..2.1......2.0......3.2......0.1......1.1......3.2......2.2......1.2
..1.2.0....3.3.2....1.3.0....2.1.2....3.2.2....2.1.1....1.1.1....1.1.1
..0.2.1.1..2.1.1.1..2.1.1.0..2.2.1.1..1.3.2.0..1.2.3.1..2.2.2.1..0.2.1.0

Crossrefs

Sequence in context: A117068 A185832 A301667 * A195951 A128068 A197095

Adjacent sequences: A195947 A195948 A195949 * A195951 A195952 A195953

Keyword

nonn

Author

R. H. Hardin Sep 25 2011

Status

approved