A267715 Number of nX4 0..1 arrays with every repeated value in every row and column greater than the previous repeated value.

9, 81, 270, 872, 1915, 4266, 7879, 14632, 24440, 40816, 63714, 99260, 147469, 218666, 312723, 446708, 619670, 859376, 1162558, 1573616, 2084223, 2764010, 3595063, 4684320, 5997316, 7694800, 9715586, 12296260, 15334641, 19171946, 23645587

Offset: 1

Author

R. H. Hardin, Jan 19 2016

Keywords

• nonn

Comments

Column 4 of A267719.

Examples

			Some solutions for n=5
..0..1..0..1....0..0..1..0....1..0..1..1....0..1..1..0....0..1..0..0
..1..0..1..0....0..1..0..0....0..1..1..0....1..0..0..1....1..0..1..0
..1..0..1..0....1..1..0..1....1..1..0..1....0..0..1..1....0..0..1..1
..0..1..0..1....1..0..1..0....0..0..1..0....0..1..1..0....1..1..0..1
..1..0..1..1....0..1..0..1....0..1..0..0....1..0..0..1....1..0..1..0
		

Links

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

Crossrefs

Cf. A267719.

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16) for n>18