A187525 - OEIS

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

6, 0, 104, 0, 9346, 0, 4278774, 0, 9966039904, 0, 118222727145122, 0, 7149579817467705382, 0, 2205539783282634028931328

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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