A266025 T(n,k)=Number of nXk integer arrays with each element equal to the number of horizontal, vertical and antidiagonal neighbors exactly one smaller than itself.
1, 3, 3, 4, 7, 4, 5, 14, 14, 5, 9, 42, 33, 42, 9, 16, 99, 91, 91, 99, 16, 25, 259, 316, 577, 316, 259, 25, 39, 719, 1045, 3796, 3796, 1045, 719, 39, 64, 1784, 3394, 19688, 39064, 19688, 3394, 1784, 64, 105, 4792, 11102, 110924, 336357, 336357, 110924, 11102, 4792, 105
Offset: 1
Examples
Some solutions for n=4 k=4 ..1..0..0..1....0..1..2..1....0..1..1..0....0..0..1..2....1..0..1..2 ..1..2..3..2....1..3..2..0....2..1..1..1....0..2..2..1....1..1..3..1 ..1..2..3..1....2..1..2..0....0..1..1..1....1..2..0..2....2..2..2..0 ..0..1..2..0....0..2..1..1....2..1..0..1....1..0..0..1....0..1..2..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..127
Crossrefs
Column 1 is A195971.
Formula
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-3) +a(n-4)
k=2: [order 21]
k=3: [order 94] for n>95
Comments