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A258538 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum less than the antidiagonal sum or central row sum equal to the central column sum. 1
220, 784, 2520, 8100, 25056, 77284, 234848, 712336, 2148108, 6471936, 19455312, 58461316, 175520864, 526886116, 1581124008, 4744454400, 14234924508, 42708355600, 128130243176, 384402480004, 1153224445824, 3459711600900 (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) = 5*a(n-1) - 32*a(n-3) + 34*a(n-4) + 54*a(n-5) - 96*a(n-6) + 63*a(n-8) - 27*a(n-9).

Empirical g.f.: 4*x*(55 - 79*x - 350*x^2 + 635*x^3 + 541*x^4 - 1473*x^5 + 183*x^6 + 918*x^7 - 432*x^8) / ((1 - x)^3*(1 + x)*(1 - 3*x)*(1 - 3*x^2)^2). - Colin Barker, Dec 21 2018

EXAMPLE

Some solutions for n=4:

..1..1..0....1..1..0....1..0..0....1..0..1....1..1..1....1..1..0....1..1..0

..0..0..0....0..0..0....0..0..0....1..0..1....1..0..0....0..1..0....1..0..1

..1..0..1....1..0..1....1..1..0....1..1..1....0..1..1....1..1..1....0..0..0

..1..0..1....0..1..0....0..0..0....1..0..1....0..0..0....0..0..1....1..1..1

..1..0..1....0..1..1....1..1..0....0..0..1....0..0..1....0..1..0....0..0..0

..1..0..1....0..1..0....0..0..0....0..0..0....1..0..1....0..1..1....1..1..1

CROSSREFS

Column 1 of A258545.

Sequence in context: A135807 A258545 A257361 * A257354 A102073 A234969

Adjacent sequences:  A258535 A258536 A258537 * A258539 A258540 A258541

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 02 2015

STATUS

approved

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Last modified November 28 21:30 EST 2021. Contains 349415 sequences. (Running on oeis4.)