A267730 Number of nX3 0..1 arrays with every repeated value in every row and column greater than or equal to the previous repeated value.
8, 64, 512, 3375, 21952, 132651, 778688, 4410944, 24389000, 131872229, 700227072, 3659383421, 18863581528, 96071912000, 484106454208, 2416353439059, 11958715956032, 58732317850311, 286451826688000, 1388285542167616
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..1....1..0..1....1..1..1....0..0..0....0..1..0....1..0..1....1..1..1 ..0..1..0....1..1..1....1..0..0....0..1..0....0..0..1....0..1..1....0..0..0 ..1..1..0....0..0..0....1..0..1....1..0..0....0..0..0....0..0..1....1..1..1 ..1..1..0....1..1..1....0..0..0....1..0..1....0..0..1....0..1..0....0..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A267735.
Formula
Empirical: a(n) = 12*a(n-1) -30*a(n-2) -120*a(n-3) +455*a(n-4) +576*a(n-5) -2142*a(n-6) -1980*a(n-7) +3180*a(n-8) +1980*a(n-9) -2142*a(n-10) -576*a(n-11) +455*a(n-12) +120*a(n-13) -30*a(n-14) -12*a(n-15) -a(n-16)
Comments