A212026 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, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-k-1

0, 0, 2, 0, 2, 9, 0, 0, 25, 31, 0, 0, 34, 346, 80, 0, 0, 35, 1793, 2589, 171, 0, 0, 35, 4785, 44294, 12636, 322, 0, 0, 0, 7396, 440660, 532619, 46612, 554, 0, 0, 0, 8220, 2655126, 14245030, 4022727, 141520, 891, 0, 0, 0, 8291, 9881099, 254601542, 231475447

Offset

1,3

Comments

Table starts

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

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

...9.....25.......34.........35...........35............0...........0

..31....346.....1793.......4785.........7396.........8220........8291

..80...2589....44294.....440660......2655126......9881099....23187213

.171..12636...532619...14245030....254601542...3122930515.26618503099

.322..46612..4022727..231475447...9411294829.279615006837

.554.141520.22156544.2383699176.187291345391

Links

R. H. Hardin, Table of n, a(n) for n = 1..84

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......1.2
..3.4.3....0.3.4....3.2.3....3.4.1....3.0.3....3.4.5....0.3.4....1.3.1
..5.6.1.7..4.5.4.5..3.4.3.5..5.0.6.0..2.4.3.5..0.2.3.1..5.6.4.1..1.4.1.5

Crossrefs

Column 1 is A211924

Sequence in context: A278748 A342286 A211930 * A246003 A242052 A344765

Adjacent sequences: A212023 A212024 A212025 * A212027 A212028 A212029

Keyword

nonn,tabl

Author

R. H. Hardin Apr 26 2012

Status

approved