A228506 T(n,k)=Number of nXk binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.
1, 1, 1, 2, 1, 2, 3, 3, 3, 3, 5, 5, 12, 5, 5, 8, 11, 29, 29, 11, 8, 13, 21, 88, 87, 88, 21, 13, 21, 43, 239, 358, 358, 239, 43, 21, 34, 85, 684, 1252, 2002, 1252, 684, 85, 34, 55, 171, 1909, 4749, 9528, 9528, 4749, 1909, 171, 55, 89, 341, 5392, 17285, 49101, 59839, 49101
Offset: 1
Examples
Some solutions for n=4 k=4 ..1..0..0..0....1..0..0..0....1..0..0..1....1..0..0..0....1..0..0..1 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0 ..0..0..0..0....1..0..0..0....0..0..0..0....0..0..0..1....1..0..0..0 ..1..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..1740
Formula
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2)
k=2: a(n) = a(n-1) +2*a(n-2)
k=3: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3)
k=4: a(n) = 2*a(n-1) +7*a(n-2) -2*a(n-3) -3*a(n-4)
k=5: a(n) = 2*a(n-1) +16*a(n-2) +a(n-3) -27*a(n-4) +a(n-5) +4*a(n-6)
k=6: [order 8]
k=7: [order 14]
Comments