A228390 T(n,k)=Number of nXk binary arrays with top left value 1 and no two ones adjacent horizontally or vertically.
1, 1, 1, 2, 2, 2, 3, 5, 5, 3, 5, 12, 21, 12, 5, 8, 29, 72, 72, 29, 8, 13, 70, 268, 382, 268, 70, 13, 21, 169, 963, 2104, 2104, 963, 169, 21, 34, 408, 3513, 11449, 17578, 11449, 3513, 408, 34, 55, 985, 12732, 62546, 143072, 143072, 62546, 12732, 985, 55, 89, 2378
Offset: 1
Examples
Some solutions for n=4 k=4 ..1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0....1..0..1..0 ..0..0..0..1....0..0..0..0....0..0..0..1....0..1..0..1....0..0..0..0 ..1..0..1..0....0..0..0..0....1..0..0..0....0..0..1..0....1..0..0..0 ..0..1..0..0....0..1..0..1....0..1..0..1....0..0..0..0....0..0..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..1860
Formula
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2)
k=2: a(n) = 2*a(n-1) +a(n-2)
k=3: a(n) = 2*a(n-1) +6*a(n-2) -a(n-4)
k=4: a(n) = 4*a(n-1) +9*a(n-2) -5*a(n-3) -4*a(n-4) +a(n-5)
k=5: [order 9]
k=6: [order 11]
k=7: [order 21]
Comments