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A187525 Number of (n+1)X(n+1) 0..1 arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation 0
6, 0, 104, 0, 9346, 0, 4278774, 0, 9966039904, 0, 118222727145122, 0, 7149579817467705382, 0, 2205539783282634028931328 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A187528

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

Some solutions for 4X4

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

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

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

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

CROSSREFS

Sequence in context: A219948 A072129 A085511 * A187696 A005212 A167028

Adjacent sequences:  A187522 A187523 A187524 * A187526 A187527 A187528

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 10 2011

STATUS

approved

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Last modified May 26 19:20 EDT 2019. Contains 323597 sequences. (Running on oeis4.)