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A253391 Number of (n+1) X (2+1) 0..1 arrays with every 2 X 2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically. 1
44, 102, 143, 197, 250, 320, 391, 477, 564, 666, 769, 887, 1006, 1140, 1275, 1425, 1576, 1742, 1909, 2091, 2274, 2472, 2671, 2885, 3100, 3330, 3561, 3807, 4054, 4316, 4579, 4857, 5136, 5430, 5725, 6035, 6346, 6672, 6999, 7341, 7684, 8042, 8401, 8775, 9150 (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) - 2*a(n-3) + a(n-4) for n>8.

Empirical for n mod 2 = 0: a(n) = 4*n^2 + (45/2)*n + 41 for n>4.

Empirical for n mod 2 = 1: a(n) = 4*n^2 + (45/2)*n + (75/2) for n>4.

Empirical g.f.: x*(44 + 14*x - 61*x^2 - x^3 + 16*x^4 + 4*x^5 + 2*x^6 - 2*x^7) / ((1 - x)^3*(1 + x)). - Colin Barker, Dec 11 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 2 of A253397.

Sequence in context: A044563 A129289 A039527 * A050944 A332590 A187933

Adjacent sequences:  A253388 A253389 A253390 * A253392 A253393 A253394

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 31 2014

STATUS

approved

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Last modified January 24 13:11 EST 2022. Contains 350538 sequences. (Running on oeis4.)