A211930 T(n,k)=Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical or antidiagonal neighbor, and containing the value n(n+1)/2-k-1

0, 0, 2, 0, 2, 9, 0, 0, 23, 31, 0, 0, 27, 340, 80, 0, 0, 27, 1685, 2577, 171, 0, 0, 27, 4151, 43607, 12616, 322, 0, 0, 0, 5809, 425384, 529891, 46582, 554, 0, 0, 0, 6093, 2484024, 14087170, 4014522, 141478, 891, 0, 0, 0, 6097, 8826873, 249499909, 230476122

Offset

1,3

Comments

Table starts

...0......0........0..........0............0..............0.............0

...2......2........0..........0............0..............0.............0

...9.....23.......27.........27...........27..............0.............0

..31....340.....1685.......4151.........5809...........6093..........6097

..80...2577....43607.....425384......2484024........8826873......19472124

.171..12616...529891...14087170....249499909.....3020833719...25290834411

.322..46582..4014522..230476122...9339489832...276214923832.6082437511849

.554.141478.22135982.2379082308.186659686448.11092305676290

Links

R. H. Hardin, Table of n, a(n) for n = 1..86

Example

Some solutions for n=4 k=4
..0........0........0........0........0........0........0........0
..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.0
..3.4.5....3.4.1....0.3.4....0.3.4....3.4.1....0.3.4....3.0.4....2.3.1
..6.7.0.6..5.3.0.6..2.5.2.4..1.5.1.4..5.0.2.4..1.5.3.4..5.6.2.4..0.4.5.0

Crossrefs

Sequence in context: A004514 A278748 A342286 * A212026 A246003 A242052

Adjacent sequences: A211927 A211928 A211929 * A211931 A211932 A211933

Keyword

nonn,tabl

Author

R. H. Hardin Apr 25 2012

Status

approved