A257443 Number of (n+2) X (4+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 1 and no column sum 1.

49, 51, 59, 71, 89, 116, 155, 212, 296, 419, 599, 863, 1250, 1817, 2648, 3866, 5651, 8267, 12101, 17720, 25955, 38024, 55712, 81635, 119627, 175307, 256910, 376505, 551780, 808658, 1185131, 1736879, 2545505, 3730604, 5467451, 8012924, 11743496

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4) for n>6.

Empirical g.f.: x*(49 - 47*x + 6*x^2 - 45*x^3 + 4*x^4 + x^5) / ((1 - x)*(1 - x - x^3)). - Colin Barker, Dec 21 2018

Example

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

Crossrefs

Column 4 of A257447.

Sequence in context: A176309 A080201 A042199 * A020276 A346805 A118073

Adjacent sequences: A257440 A257441 A257442 * A257444 A257445 A257446

Keyword

nonn

Author

R. H. Hardin, Apr 23 2015

Status

approved