A267724 T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with every element equal to at least one horizontal neighbor and the top left element equal to 0.
0, 1, 0, 1, 1, 0, 1, 1, 2, 0, 1, 3, 2, 6, 0, 1, 5, 30, 6, 24, 0, 1, 12, 58, 630, 24, 120, 0, 1, 26, 588, 1398, 22680, 120, 720, 0, 1, 60, 2388, 93672, 55896, 1247400, 720, 5040, 0, 1, 143, 17456, 609264, 33807456, 3353880, 97297200, 5040, 40320, 0, 1, 353, 102874
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..0..2..2....0..0..0..0....0..0..1..1....0..0..2..2....0..0..3..3 ..2..2..0..0....3..3..3..3....3..3..2..2....1..1..0..0....1..1..2..2 ..1..1..3..3....2..2..1..1....0..0..2..2....3..3..2..2....1..1..2..2 ..3..3..1..1....2..2..1..1....3..3..1..1....3..3..1..1....0..0..3..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..70
Comments