A195277 Number of lower triangles of an n X n integer array with each element differing from all of its vertical and horizontal neighbors by 7 or less and triangles differing by a constant counted only once

1, 225, 507375, 11755976175, 2834518121474625, 7151051711514319493625, 189393562987102056163761489375

Offset

1,2

Comments

Column 7 of A195278

Links

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

Example

Some solutions for n=5
...0...............0...............0...............0...............0
..-5.-7...........-1.-5...........-7.-7...........-1.-8............4..6
..-8.-9.-8.........5..2..9........-7-14-17.........2.-4-11........-1.-1.-2
..-1.-2.-3..1.....-1.-5..2..8.....-4.-7-14-10......1.-1.-5.-7......2..4..4.-3
...5..3..3..5..6..-3.-2..5..9..6..-2.-5.-8-12-12..-1..4..0.-7-14...4..3..4.-3.-1

Crossrefs

Sequence in context: A239478 A304314 A109688 * A319944 A013757 A151653

Adjacent sequences: A195274 A195275 A195276 * A195278 A195279 A195280

Keyword

nonn

Author

R. H. Hardin Sep 14 2011

Status

approved