A267718 Number of nX7 0..1 arrays with every repeated value in every row and column greater than the previous repeated value.
20, 400, 1866, 7879, 20226, 54887, 116036, 255009, 481390, 932245, 1627470, 2893983, 4765598, 7967260, 12535320, 20000374, 30337594, 46665892, 68699820, 102616722, 147369478, 214889742, 302259706, 431988823, 597033836, 838908027
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..1..0..1..0..1....0..1..0..1..0..1..1....1..0..1..0..1..0..0 ..1..1..0..1..0..1..0....1..1..0..1..0..1..0....0..1..0..1..0..1..0 ..1..0..1..0..1..0..1....0..0..1..0..1..0..1....1..0..1..0..1..0..1 ..0..0..1..1..0..1..0....0..1..0..1..0..1..0....0..1..0..0..1..1..0 ..1..1..0..1..0..1..0....1..0..1..0..1..0..0....0..1..0..1..0..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A267719.
Formula
Empirical: a(n) = 2*a(n-1) +12*a(n-2) -26*a(n-3) -65*a(n-4) +156*a(n-5) +208*a(n-6) -572*a(n-7) -429*a(n-8) +1430*a(n-9) +572*a(n-10) -2574*a(n-11) -429*a(n-12) +3432*a(n-13) -3432*a(n-15) +429*a(n-16) +2574*a(n-17) -572*a(n-18) -1430*a(n-19) +429*a(n-20) +572*a(n-21) -208*a(n-22) -156*a(n-23) +65*a(n-24) +26*a(n-25) -12*a(n-26) -2*a(n-27) +a(n-28) for n>30
Comments