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.
A187670
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.
Terms
- a(0) =6a(1) =50a(2) =24a(3) =192a(4) =550a(5) =112a(6) =512a(7) =4044a(8) =11282a(9) =974a(10) =1126a(11) =17716a(12) =174292a(13) =612204a(14) =9928a(15) =2146a(16) =56080a(17) =1549398a(18) =36461174a(19) =65533922a(20) =197152a(21) =3760a(22) =150166a(23) =6839146a(24) =835707780
External references
- oeis: A187670