A207303 Number of n X 6 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

19, 361, 1675, 4939, 11497, 23091, 41893, 70537, 112151, 170389, 249463, 354175, 489949, 662863, 879681, 1147885, 1475707, 1872161, 2347075, 2911123, 3575857, 4353739, 5258173, 6303537, 7505215, 8879629, 10444271, 12217735, 14219749

Offset

1,1

Comments

Column 6 of A207305.

Links

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

Formula

Empirical: a(n) = (4/15)*n^5 + (45/4)*n^4 + (199/6)*n^3 - (73/4)*n^2 - (373/30)*n + 5.

Conjectures from Colin Barker, Jun 21 2018: (Start)

G.f.: x*(19 + 247*x - 206*x^2 - 76*x^3 + 53*x^4 - 5*x^5) / (1 - x)^6.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6. (End)

Example

Some solutions for n=4:
..1..0..0..1..0..0....1..1..0..0..1..1....0..0..1..0..0..1....0..0..1..0..0..1
..0..1..0..0..1..0....1..1..1..1..0..0....1..0..0..1..1..0....0..1..1..0..0..1
..1..1..0..0..1..0....1..1..0..0..1..1....1..0..0..1..0..0....0..1..1..0..0..1
..1..1..0..0..1..0....1..1..1..0..0..1....1..0..0..1..1..0....0..1..1..0..0..1

Crossrefs

Cf. A207305.

Sequence in context: A207167 A208011 A207788 * A207916 A208162 A207958

Adjacent sequences: A207300 A207301 A207302 * A207304 A207305 A207306

Keyword

nonn

Author

R. H. Hardin, Feb 16 2012

Status

approved