login
T(n,k)=Number of (n+1)X(n+1) 0..k arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal
4

%I #4 Mar 31 2012 12:36:09

%S 6,50,24,192,550,112,512,4044,11282,974,1126,17716,174292,612204,9928,

%T 2146,56080,1549398,36461174,65533922,197152,3760,150166,6839146,

%U 835707780

%N T(n,k)=Number of (n+1)X(n+1) 0..k arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal

%C Table starts

%C ......6.......50......192.......512....1126...2146.3760

%C .....24......550.....4044.....17716...56080.150166

%C ....112....11282...174292...1549398.6839146

%C ....974...612204.36461174.835707780

%C ...9928.65533922

%C .197152

%e Some k=3 solutions for 5X5

%e ..0..2..2..0..3....0..2..2..2..3....0..2..2..2..1....0..2..2..2..3

%e ..2..1..0..1..0....2..2..0..1..1....2..2..0..1..1....2..2..0..1..1

%e ..2..0..3..0..2....2..0..2..0..2....2..0..1..1..3....2..0..1..0..2

%e ..0..1..0..1..2....0..1..0..2..2....3..1..0..2..2....0..1..0..2..3

%e ..3..2..2..2..0....1..1..2..3..1....2..1..2..2..0....1..1..2..2..1

%Y Row 1 is A062801

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_ Mar 12 2011