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A187622 Number of (n+1)X(n+1) 0..2 arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation 0
31, 446, 60, 324452, 70548, 6090023738, 720252796 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A187624

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

Some solutions for 4X4

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

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

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

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

CROSSREFS

Sequence in context: A022723 A332909 A084234 * A187630 A118196 A160443

Adjacent sequences:  A187619 A187620 A187621 * A187623 A187624 A187625

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 12 2011

STATUS

approved

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Last modified November 27 09:19 EST 2021. Contains 349365 sequences. (Running on oeis4.)