A268015 Number of nX3 0..2 arrays with every repeated value in every row and column greater than or equal to the previous repeated value.
27, 729, 19683, 474552, 10941048, 240641848, 5106219048, 105087226959, 2107490863661, 41332013859375, 794974954718853, 15030454569975872, 279880270014528000, 5140991504979000000, 93278442949595408448
Offset: 1
Keywords
Examples
Some solutions for n=3 ..2..0..2....2..0..2....2..2..0....0..0..2....1..1..0....0..2..0....2..0..2 ..0..0..2....1..0..2....2..0..1....2..2..0....0..1..2....2..1..1....0..2..2 ..1..2..0....0..1..2....1..0..2....0..0..0....0..2..0....1..2..0....2..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268019.
Formula
Empirical: a(n) = 84*a(n-1) -2814*a(n-2) +45276*a(n-3) -285019*a(n-4) -1063944*a(n-5) +20124468*a(n-6) -1605816*a(n-7) -630123753*a(n-8) -402925572*a(n-9) +10392502302*a(n-10) +30566899188*a(n-11) +12457260613*a(n-12) -49186967088*a(n-13) -30986023080*a(n-14) +49186967088*a(n-15) +12457260613*a(n-16) -30566899188*a(n-17) +10392502302*a(n-18) +402925572*a(n-19) -630123753*a(n-20) +1605816*a(n-21) +20124468*a(n-22) +1063944*a(n-23) -285019*a(n-24) -45276*a(n-25) -2814*a(n-26) -84*a(n-27) -a(n-28)
Comments