A207981 T(n,k)=Number of n X k nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).
1, 2, 2, 5, 7, 5, 15, 67, 67, 15, 52, 1080, 4192, 1080, 52, 203, 25287, 587208, 587208, 25287, 203, 877, 794545, 147512732, 953124784, 147512732, 794545, 877, 4140, 31858034, 58668937932, 3410310590912, 3410310590912, 58668937932, 31858034
Offset: 1
Examples
Table starts ....1........2...........5............15............52...............203 ....2........7..........67..........1080.........25287............794545 ....5.......67........4192........587208.....147512732.......58668937932 ...15.....1080......587208.....953124784.3410310590912.22727131144960768 ...52....25287...147512732.3410310590912 ..203...794545.58668937932 ..877.31858034 .4140 ... Some solutions for n=4 k=3 ..0..0..0....0..0..1....0..0..0....0..0..0....0..1..0....0..0..0....0..0..0 ..1..1..1....1..2..1....1..1..1....1..1..1....2..1..0....1..2..1....1..1..1 ..2..0..2....1..2..0....0..0..2....0..0..0....0..1..3....0..0..0....2..2..0 ..1..0..1....0..2..0....1..1..1....1..1..1....0..4..0....2..1..1....0..1..0
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..496 (terms 1..40 from R. H. Hardin).