A203981 Number of (n+1) X 6 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

1536, 31104, 629856, 13071456, 271918944, 5671161216, 118333620576, 2469841766784, 51553851826176, 1076137623724896, 22463572543638624, 468912308350736736, 9788249148960940416, 204323642334833818464

Offset: 1

Author

R. H. Hardin, Jan 09 2012

Keywords

• nonn

Comments

Column 5 of A203984.

Examples

			Some solutions for n=4:
..0..0..0..0..0..0....0..0..0..1..0..0....0..0..0..0..0..0....0..0..0..1..2..2
..1..1..1..1..2..2....1..1..2..2..2..2....1..1..2..2..1..1....1..1..2..1..0..0
..2..2..2..0..0..1....2..0..0..1..1..1....2..0..0..0..0..2....0..0..2..1..2..2
..1..1..1..1..2..1....1..1..2..2..0..0....2..1..2..2..1..2....2..1..2..0..0..0
..0..2..2..0..0..1....0..0..0..1..1..1....0..0..0..0..0..2....2..0..2..1..1..1
		

Links

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

Crossrefs

Cf. A203984.

Formula

Empirical: a(n) = 25*a(n-1) - 45*a(n-2) - 963*a(n-3) + 2025*a(n-4) + 3645*a(n-5) - 6561*a(n-6).

Empirical g.f.: 96*x*(16 - 76*x - 819*x^2 + 2124*x^3 + 3321*x^4 - 6561*x^5) / ((1 - 25*x + 90*x^2 - 81*x^3)*(1 - 45*x^2 - 81*x^3)). - Colin Barker, Jun 06 2018