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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. 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 (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) = 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

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Last modified September 25 00:48 EDT 2020. Contains 337333 sequences. (Running on oeis4.)