A267788 T(n,k)=Number of nXk 0..1 arrays with every repeated value in every row greater than or equal to, and in every column greater than, the previous repeated value.
2, 4, 4, 8, 16, 6, 15, 64, 36, 9, 28, 225, 216, 81, 12, 51, 784, 1056, 729, 144, 16, 92, 2601, 5004, 5081, 1728, 256, 20, 164, 8464, 22110, 34173, 14956, 4096, 400, 25, 290, 26896, 94554, 211555, 122770, 44742, 8000, 625, 30, 509, 84100, 391314, 1262760, 912667
Offset: 1
Examples
Some solutions for n=4 k=4 ..1..0..1..0....1..0..0..0....0..1..0..0....1..1..1..0....1..1..0..1 ..0..1..0..1....1..1..0..1....0..0..0..0....0..0..0..0....0..0..0..0 ..0..0..1..0....0..0..1..1....1..1..1..1....0..1..0..1....1..1..1..1 ..1..1..1..1....1..0..0..0....1..0..1..0....1..1..1..1....1..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) -2*a(n-3) +a(n-4)
k=2: a(n) = 2*a(n-1) +2*a(n-2) -6*a(n-3) +6*a(n-5) -2*a(n-6) -2*a(n-7) +a(n-8)
k=3: [order 12]
k=4: [order 16] for n>18
k=5: [order 20] for n>22
k=6: [order 24] for n>27
Empirical for row n:
n=1: a(n) = 2*a(n-1) +a(n-2) -2*a(n-3) -a(n-4)
n=2: [order 9]
n=3: [order 12]
n=4: [order 93]
Comments