A207451 Number of n X 6 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 0 1 vertically.
26, 676, 3354, 10088, 23530, 46956, 84266, 139984, 219258, 327860, 472186, 659256, 896714, 1192828, 1556490, 1997216, 2525146, 3151044, 3886298, 4742920, 5733546, 6871436, 8170474, 9645168, 11310650, 13182676, 15277626, 17612504, 20204938
Offset: 1
Keywords
Examples
Some solutions for n=5: 1 0 1 0 1 1 0 1 1 0 1 0 1 1 1 0 1 0 1 1 0 1 1 0 1 1 1 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 1 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A207453.
Formula
Empirical: a(n) = 26*n^4 + 78*n^3 - 104*n^2 + 26*n.
Conjectures from Colin Barker, Jun 23 2018: (Start)
G.f.: 26*x*(1 + 21*x + 9*x^2 - 7*x^3) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
Comments