A187626 - OEIS

A187626

Number of 4X4 0..n arrays with each 2X2 non-center subblock determinant nonzero and the array of 2X2 subblock determinants antisymmetric under 90 degree rotation

2, 60, 390, 2146, 5324, 16042, 28916, 71012, 121678, 216768, 302470, 606282, 785548

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OFFSET

1,1

COMMENTS

Row 3 of A187624

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Some n=3 solutions for 4X4

..1..3..0..3....1..0..2..1....3..2..0..2....3..1..0..3....2..2..0..2

..0..3..1..3....3..1..1..0....2..2..1..2....0..3..3..1....0..2..2..3

..1..3..1..0....1..1..1..2....3..2..1..0....1..3..3..0....2..2..2..1

..2..3..2..3....3..2..0..1....1..0..1..2....3..0..1..3....2..0..2..3

CROSSREFS

Sequence in context: A275819 A048541 A067739 * A059934 A006333 A001760

Adjacent sequences: A187623 A187624 A187625 * A187627 A187628 A187629

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 12 2011

STATUS

approved