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A251087 Number of (n+1) X (7+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
3593, 9086, 15411, 28616, 48017, 82898, 139553, 240972, 420611, 755534, 1387095, 2607904, 4990157, 9687898, 18995941, 37513316, 74424559, 148107894, 295305995, 589513112, 1177703721, 2353835426, 4705809161, 9409435196, 18816319547 (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*(3593 - 12472*x + 7604*x^2 + 18338*x^3 - 32161*x^4 + 17566*x^5 - 1962*x^6 - 756*x^7) / ((1 - x)^5*(1 + x)*(1 - 2*x)). - Colin Barker, Nov 24 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 7 of A251088.

Sequence in context: A342970 A284970 A183007 * A187422 A186214 A188100

Adjacent sequences: A251084 A251085 A251086 * A251088 A251089 A251090

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 29 2014

STATUS

approved

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Last modified December 6 19:33 EST 2022. Contains 358648 sequences. (Running on oeis4.)