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A187621 Number of (n+1)X(n+1) 0..1 arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation 0

%I

%S 10,24,2,948,36,190972,3020,194618700,929380,1018751442652,1744283776,

%T 27189851221308572,15262275217840

%N Number of (n+1)X(n+1) 0..1 arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation

%C Column 1 of A187624

%e All solutions for 4X4

%e ..1..1..0..1....1..0..1..1

%e ..0..1..1..1....1..1..1..0

%e ..1..1..1..0....0..1..1..1

%e ..1..0..1..1....1..1..0..1

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 12 2011

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Last modified December 5 08:36 EST 2021. Contains 349543 sequences. (Running on oeis4.)