A206249 Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having zero permanent.

361, 8029, 99856, 1718209, 26512201, 434613664, 6990799321, 113636628469, 1841188465216, 29885540089249, 484822312979761, 7867521981505504, 127659187514359081, 2071519703855856109, 33613908262858076176

Offset: 1

Author

R. H. Hardin, Feb 05 2012

Keywords

• nonn

Comments

Column 2 of A206255.

Examples

			Some solutions for n=4:
..0..2..3....0..2..0....0..0..3....3..0..1....1..2..2....0..3..3....2..3..0
..0..0..0....0..0..0....1..0..1....0..0..1....0..0..0....0..0..0....0..0..0
..1..1..1....1..3..2....0..0..3....0..0..1....1..1..1....1..0..0....3..3..3
..0..0..0....0..0..0....2..0..3....1..0..0....0..0..0....1..0..3....0..0..0
..3..1..3....1..0..1....2..0..1....3..0..1....0..0..2....2..0..1....1..1..0
		

Links

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

Crossrefs

Cf. A206255.

Formula

Empirical: a(n) = 19*a(n-1) - 855*a(n-3) + 2025*a(n-4).

Empirical g.f.: x*(361 + 1170*x - 52695*x^2 + 129600*x^3) / ((1 - 19*x + 45*x^2)*(1 - 45*x^2)). - Colin Barker, Jun 14 2018