A212041 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 within a city block distance of two, and containing the value n(n+1)/2-4

0, 0, 5, 319, 14949, 253072, 2326567, 14516200, 69305994, 271885024, 917364452, 2746402607, 7459357270

Offset

1,3

Comments

Column 3 of A212044

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for n=4
..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....3.4.5....3.4.1....3.4.0....3.0.4....3.4.5....3.4.5....3.0.4
..5.6.2.5..0.6.7.3..5.0.6.4..5.6.7.2..5.6.3.0..6.0.1.3..0.6.7.1..2.1.5.6

Crossrefs

Sequence in context: A366305 A130308 A304212 * A251696 A366329 A274306

Adjacent sequences: A212038 A212039 A212040 * A212042 A212043 A212044

Keyword

nonn

Author

R. H. Hardin Apr 28 2012

Status

approved