A267245 T(n,k)=Number of nXk binary arrays with row sums nondecreasing and columns lexicographically nondecreasing.
2, 3, 3, 4, 7, 4, 5, 13, 15, 5, 6, 22, 42, 31, 6, 7, 34, 105, 141, 63, 7, 8, 50, 232, 567, 486, 127, 8, 9, 70, 475, 1986, 3351, 1685, 255, 9, 10, 95, 904, 6292, 20040, 20676, 5804, 511, 10, 11, 125, 1632, 18205, 107015, 220235, 129129, 19769, 1023, 11, 12, 161, 2806
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..0..1..1....0..0..0..1....0..0..1..1....0..0..1..1....0..0..1..1 ..0..1..1..1....0..1..1..0....0..1..0..1....1..1..0..0....1..1..0..0 ..1..0..1..1....0..0..1..1....1..1..0..0....1..1..0..1....1..1..0..0 ..1..1..0..1....1..0..1..0....1..1..0..0....1..1..1..0....1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..216
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) -a(n-2)
k=2: a(n) = 3*a(n-1) -2*a(n-2)
k=3: a(n) = 10*a(n-1) -39*a(n-2) +76*a(n-3) -79*a(n-4) +42*a(n-5) -9*a(n-6)
k=4: [order 10]
k=5: [order 14]
k=6: [order 22]
k=7: [order 32]
Empirical for row n:
n=1: a(n) = 2*a(n-1) -a(n-2)
n=2: a(n) = 3*a(n-1) -2*a(n-2) -2*a(n-3) +3*a(n-4) -a(n-5)
n=3: [order 13]
Comments