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A253158 Number of (n+1) X (7+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically. 1
613, 624, 633, 668, 740, 884, 1172, 1748, 2900, 5204, 9812, 19028, 37460, 74324, 148052, 295508, 590420, 1180244, 2359892, 4719188, 9437780, 18874964, 37749332, 75498068, 150995540, 301990484, 603980372, 1207960148, 2415919700, 4831838804 (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) = 3*a(n-1) - 2*a(n-2) for n>5.

Empirical: a(n) = 9*2^(n-1) + 596 for n>3.

Empirical g.f.: x*(613 - 1215*x - 13*x^2 + 17*x^3 + 2*x^4) / ((1 - x)*(1 - 2*x)). - Colin Barker, Dec 09 2018

EXAMPLE

Some solutions for n=6:

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

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

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

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

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

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

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

CROSSREFS

Column 7 of A253159.

Sequence in context: A292036 A253434 A253441 * A159641 A100364 A142435

Adjacent sequences:  A253155 A253156 A253157 * A253159 A253160 A253161

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 28 2014

STATUS

approved

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Last modified May 19 14:52 EDT 2022. Contains 353834 sequences. (Running on oeis4.)