A257446 Number of (n+2) X (7+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.

128, 134, 143, 155, 173, 200, 239, 296, 380, 503, 683, 947, 1334, 1901, 2732, 3950, 5735, 8351, 12185, 17804, 26039, 38108, 55796, 81719, 119711, 175391, 256994, 376589, 551864, 808742, 1185215, 1736963, 2545589, 3730688, 5467535, 8013008

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).

Empirical g.f.: x*(128 - 122*x + 3*x^2 - 125*x^3) / ((1 - x)*(1 - x - x^3)). - Colin Barker, Dec 21 2018

Example

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

Crossrefs

Column 7 of A257447.

Sequence in context: A217847 A223591 A097758 * A130445 A114565 A243812

Adjacent sequences: A257443 A257444 A257445 * A257447 A257448 A257449

Keyword

nonn

Author

R. H. Hardin, Apr 23 2015

Status

approved