A207457 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 0 1 vertically.

12, 144, 396, 2460, 9216, 46956, 196812, 932688, 4086060, 18819228, 83939328, 382160076, 1717133964, 7780911120, 35067371724, 158593617564, 715647771648, 3233959733292, 14600607874380, 65957362026192, 297845692391532

Offset: 1

Author

R. H. Hardin, Feb 17 2012

Keywords

• nonn

Comments

Row 6 of A207453.

Examples

			Some solutions for n=5:
  1 0 1 1 0     0 1 1 1 1     1 0 1 0 1     1 0 1 0 1
  1 1 0 1 1     0 1 0 1 1     0 1 1 1 0     1 0 1 0 1
  0 1 0 1 0     0 1 0 1 0     0 1 0 1 0     1 0 1 0 1
  0 1 0 1 0     0 1 0 1 0     0 1 0 1 0     1 0 1 0 0
  0 1 0 1 0     0 1 0 1 0     0 1 0 1 0     1 0 1 0 0
  0 1 0 1 0     0 1 0 1 0     0 1 0 1 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) = a(n-1) + 16*a(n-2) + 5*a(n-3) - 25*a(n-4).

Empirical g.f.: 12*x*(1 + 11*x + 5*x^2 - 25*x^3) / (1 - x - 16*x^2 - 5*x^3 + 25*x^4). - Colin Barker, Jun 23 2018