A188821 Number of n X 6 binary arrays without the pattern 0 1 diagonally or antidiagonally.
64, 441, 1296, 2704, 4624, 7056, 10000, 13456, 17424, 21904, 26896, 32400, 38416, 44944, 51984, 59536, 67600, 76176, 85264, 94864, 104976, 115600, 126736, 138384, 150544, 163216, 176400, 190096, 204304, 219024, 234256, 250000, 266256, 283024
Offset: 1
Keywords
Examples
Some solutions for 3 X 6: ..0..1..1..1..1..1....1..1..1..1..1..1....1..0..1..1..1..1....0..1..0..1..1..1 ..0..0..1..0..1..0....0..1..1..1..1..1....0..1..0..1..0..1....1..0..1..0..1..1 ..0..0..0..1..0..0....0..0..1..1..1..1....1..0..1..0..1..0....0..1..0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Crossrefs
Cf. A188824.
Formula
Empirical: a(n) = 256*n^2 - 384*n + 144 for n>2.
Conjectures from Colin Barker, Apr 30 2018: (Start)
G.f.: x*(64 + 249*x + 165*x^2 + 75*x^3 - 41*x^4) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>5.
(End)
Comments