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 A187706 Number of 3X3 0..n arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal 1
 128, 1489, 8272, 31461, 93476, 235773, 524284, 1062857, 1999212, 3541677, 5967404, 9648841, 15048584, 22766353, 33534080, 48248321, 67983232, 94042589, 127929948, 171449249, 226655576, 295941137, 382036240, 488090685, 617595596, 774557293 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 2 of A187705 LINKS R. H. Hardin, Table of n, a(n) for n = 1..33 EXAMPLE Some n=3 solutions for 3X3 ..3..0..0....2..0..3....0..0..1....3..1..1....0..0..3....2..0..0....2..0..0 ..2..0..3....2..0..0....3..0..1....0..0..0....0..0..3....1..0..0....0..0..0 ..1..0..0....1..0..0....2..0..3....3..2..1....3..0..1....0..0..3....0..2..2 CROSSREFS Sequence in context: A070055 A247930 A200842 * A202961 A239540 A327772 Adjacent sequences: A187703 A187704 A187705 * A187707 A187708 A187709 KEYWORD nonn AUTHOR R. H. Hardin Mar 12 2011 STATUS approved

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Last modified December 2 19:57 EST 2023. Contains 367526 sequences. (Running on oeis4.)