A212033 Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any element at a city block distance of two, and containing the value n(n+1)/2-4

0, 0, 34, 1651, 39901, 480914, 3668669, 20431909, 90528036, 337143876, 1095367909, 3187460809

Offset

1,3

Comments

Column 3 of A212036

Links

Table of n, a(n) for n=1..12.

Example

Some solutions for n=4
..0........0........0........0........0........0........0........0
..1.2......1.2......1.2......0.1......1.2......1.2......1.2......1.2
..3.4.5....3.4.5....3.4.5....2.1.0....1.3.3....3.2.0....3.4.5....3.4.0
..2.0.6.7..6.7.7.2..6.0.5.4..3.4.5.6..4.0.5.6..4.5.3.6..6.0.2.7..2.5.6.3

Crossrefs

Sequence in context: A212735 A123790 A297636 * A202297 A296673 A086881

Adjacent sequences: A212030 A212031 A212032 * A212034 A212035 A212036

Keyword

nonn

Author

R. H. Hardin Apr 27 2012

Status

approved