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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. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 2 15:00 EST 2022. Contains 358510 sequences. (Running on oeis4.)