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

1,1

Comments

Column 6 of A207453.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

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)

Example

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

Crossrefs

Cf. A207453.

Sequence in context: A207772 A207899 A207659 * A208553 A262271 A207921

Adjacent sequences: A207448 A207449 A207450 * A207452 A207453 A207454

Keyword

nonn

Author

R. H. Hardin, Feb 17 2012

Status

approved