A207593 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 1 vertically.

18, 324, 612, 2232, 7272, 25776, 85536, 300096, 1004364, 3501756, 11782620, 40900716, 138145104, 477983232, 1619007480, 5587936560, 18968405364, 65343675996, 222184777860, 764259590844, 2602091320056, 8940128392080

Offset: 1

Author

R. H. Hardin, Feb 19 2012

Keywords

• nonn

Comments

Row 6 of A207589.

Examples

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

Links

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

Crossrefs

Cf. A207589.

Formula

Empirical: a(n) = -a(n-1) + 16*a(n-2) + 18*a(n-3) - 61*a(n-4) - 61*a(n-5) + 66*a(n-6) + 58*a(n-7) - 8*a(n-8) - 8*a(n-9) for n>11.

Empirical g.f.: 18*x*(1 + 19*x + 36*x^2 - 148*x^3 - 279*x^4 + 399*x^5 + 594*x^6 - 368*x^7 - 410*x^8 + 44*x^9 + 52*x^10) / (1 + x - 16*x^2 - 18*x^3 + 61*x^4 + 61*x^5 - 66*x^6 - 58*x^7 + 8*x^8 + 8*x^9). - Colin Barker, Jun 24 2018