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A254560 Number of (n+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the four sums of the central row, central column, diagonal and antidiagonal nondecreasing horizontally and vertically 1
512, 10870, 312322, 2148260, 10679860, 67038844, 206491388, 1250249820, 5063238114, 28541610636, 134752005110, 745481127674, 3775535862318, 20661615040104, 108055326376786, 586769234129672, 3112281471218398 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Diagonal of A254568

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..29

EXAMPLE

Some solutions for n=2

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

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

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

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

CROSSREFS

Sequence in context: A344305 A254797 A254837 * A257182 A288776 A200844

Adjacent sequences:  A254557 A254558 A254559 * A254561 A254562 A254563

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 01 2015

STATUS

approved

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Last modified August 2 01:19 EDT 2021. Contains 346408 sequences. (Running on oeis4.)