A187458
Number of (n+1)X(n+1) 0..1 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
6, 26, 144, 1272, 15192, 286392, 7648032, 314011868, 18986004296, 1725663296600, 237096836118080, 48071903199959400, 15027587384189632928, 6819730931931151055960, 4852231403635188536789728
Offset: 1
Some solutions for 4X4
..1..1..0..1....1..0..1..1....0..1..0..1....1..0..1..1....1..0..1..0
..1..0..1..0....0..1..0..1....1..0..1..0....0..1..0..1....1..1..1..1
..0..1..0..1....1..0..1..1....1..1..0..1....1..0..1..1....1..0..1..0
..1..0..1..1....0..1..0..1....1..0..1..1....1..1..1..0....0..1..1..1
A187463
Number of 3X3 0..n arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
26, 1236, 13726, 84048, 325932, 1118854, 2843394, 6976192, 14900828, 30426976, 54176690, 102373984, 165774050, 274508960, 439528372, 685793860, 988022550, 1499573556, 2077344368, 3019161806, 4198346324, 5736736398, 7500683014
Offset: 1
A187459
Number of (n+1)X(n+1) 0..2 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
50, 1236, 89618, 11684688, 6112320620, 4871877392202, 17264863350746654, 83050637417670542044
Offset: 1
Some solutions for 4X4
..2..2..2..0....1..1..1..2....1..1..2..0....2..1..2..2....0..2..0..2
..1..2..0..2....0..2..0..1....2..1..0..2....1..2..1..0....2..0..2..2
..2..0..1..1....1..0..2..2....2..0..1..0....2..1..2..2....0..2..1..2
..2..2..2..0....2..1..2..0....2..2..2..2....2..0..2..0....2..2..2..0
A187460
Number of (n+1)X(n+1) 0..3 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
192, 13726, 5098224, 3387715318, 19708386669940, 150657364854061134
Offset: 1
Some solutions for 5X5
..0..2..2..0..1....0..2..2..0..1....0..2..2..0..1....0..2..2..0..2
..2..2..0..2..1....2..2..0..2..0....2..2..0..2..1....2..2..0..2..2
..2..0..1..0..1....2..0..3..0..2....2..0..3..0..3....2..0..2..0..1
..0..2..0..1..3....0..2..0..2..1....0..2..0..2..1....0..2..0..2..0
..1..2..1..2..3....1..2..2..1..0....1..1..3..3..3....2..1..1..3..1
A187461
Number of (n+1)X(n+1) 0..4 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
512, 84048, 100936174, 216668424092, 7540469990506332
Offset: 1
Some solutions for 4X4
..0..1..1..2....0..1..0..2....0..1..2..1....0..1..0..4....0..1..0..2
..1..0..1..4....1..0..1..0....1..0..2..0....1..0..1..0....1..0..1..3
..1..1..1..0....1..1..0..3....1..2..3..1....4..1..4..3....0..1..1..2
..2..4..0..1....3..1..3..1....2..2..4..3....4..0..3..1....2..1..0..3
A187464
Number of 4X4 0..n arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
144, 89618, 5098224, 100936174, 1061948616, 7706500654, 41131010240, 180898687166, 670434819776, 2192125079476, 6398465414348, 17262285779402
Offset: 1
A187465
Number of 5X5 0..n arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.
Original entry on oeis.org
1272, 11684688, 3387715318, 216668424092, 5212823523842, 83101128839744
Offset: 1
Showing 1-7 of 7 results.
Comments