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A251083 Number of (n+1) X (3+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
192, 616, 1165, 2362, 4379, 8284, 15411, 29142, 55429, 106880, 207889, 407938, 805159, 1596500, 3175015, 6327486, 12626625, 25218520, 50394485, 100737802, 201414163, 402755596, 805425275, 1610750182, 3221383389, 6442631664 (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.: x*(192 - 536*x - 35*x^2 + 1460*x^3 - 1768*x^4 + 674*x^5 + 85*x^6 - 82*x^7) / ((1 - x)^5*(1 + x)*(1 - 2*x)). - Colin Barker, Nov 24 2018

EXAMPLE

Some solutions for n=4:

..0..0..1..1....0..0..0..2....1..1..2..2....0..0..0..2....1..0..0..2

..0..0..0..0....1..0..0..1....0..0..0..0....0..0..0..2....1..0..0..2

..0..0..0..0....2..0..0..1....1..1..1..1....1..0..0..0....1..0..0..2

..0..0..0..0....2..0..0..1....0..0..0..0....1..0..0..0....1..0..0..2

..1..1..1..1....2..0..0..1....2..2..1..1....2..1..1..1....2..0..0..0

CROSSREFS

Column 3 of A251088.

Sequence in context: A232940 A254854 A254847 * A194647 A054001 A051527

Adjacent sequences:  A251080 A251081 A251082 * A251084 A251085 A251086

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 29 2014

STATUS

approved

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Last modified February 24 03:22 EST 2020. Contains 332195 sequences. (Running on oeis4.)