cp's OEIS Frontend

A187528 T(n,k)=Number of (n+1)X(n+1) 0..k arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation.

%I A187528 #6 Jul 22 2025 10:48:33
%S A187528 6,50,0,192,8,104,512,74,3790,0,1126,280,35026,1476,9346,2146,784,
%T A187528 220802,20554,3607148,0,3760,1970,727842,273102,164460556,296232,
%U A187528 4278774,6112,3580,2327574,992410
%N A187528 T(n,k)=Number of (n+1)X(n+1) 0..k arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation.
%C A187528 Table starts
%C A187528 .......6......50.......192....512...1126....2146.3760.6112
%C A187528 .......0.......8........74....280....784....1970.3580
%C A187528 .....104....3790.....35026.220802.727842.2327574
%C A187528 .......0....1476.....20554.273102.992410
%C A187528 ....9346.3607148.164460556
%C A187528 .......0..296232
%C A187528 .4278774
%e A187528 Some k=3 solutions for 5X5
%e A187528 ..1..2..3..1..1....1..2..3..1..3....3..2..1..1..2....1..1..3..2..3
%e A187528 ..0..2..2..0..2....0..3..3..0..3....1..0..1..2..2....3..0..3..3..3
%e A187528 ..1..2..3..1..2....1..2..3..1..3....2..1..1..1..2....2..1..2..1..2
%e A187528 ..1..0..1..1..0....2..1..3..2..3....2..2..1..0..1....3..3..3..0..3
%e A187528 ..2..2..3..1..2....1..2..3..1..3....2..1..1..2..1....2..1..2..1..2
%Y A187528 Row 1 is A062801
%K A187528 nonn,tabl
%O A187528 1,1
%A A187528 _R. H. Hardin_ Mar 10 2011