A251086 Number of (n+1) X (6+1) 0..2 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

1782, 4848, 8284, 15780, 27040, 47932, 82898, 147152, 263698, 484744, 907152, 1730716, 3347340, 6546772, 12900694, 25558280, 50809934, 101242144, 202019812, 403478292, 806280088, 1611755628, 3222557434, 6443995840, 12886683050

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) - 13*a(n-2) + 10*a(n-3) + 5*a(n-4) - 14*a(n-5) + 9*a(n-6) - 2*a(n-7) for n>8.

Empirical g.f.: 2*x*(891 - 2922*x + 1181*x^2 + 5640*x^3 - 8669*x^4 + 4350*x^5 - 280*x^6 - 256*x^7) / ((1 - x)^5*(1 + x)*(1 - 2*x)). - Colin Barker, Nov 24 2018

Example

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

Crossrefs

Column 6 of A251088.

Sequence in context: A253057 A204637 A023088 * A255157 A175693 A317628

Adjacent sequences: A251083 A251084 A251085 * A251087 A251088 A251089

Keyword

nonn

Author

R. H. Hardin, Nov 29 2014

Status

approved