A187670 - cp's OEIS frontend

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.

n	a(n)
1	6
2	50
3	24
4	192
5	550
6	112
7	512
8	4044
9	11282
10	974
11	1126
12	17716
13	174292
14	612204
15	9928
16	2146
17	56080
18	1549398
19	36461174
20	65533922
21	197152
22	3760
23	150166
24	6839146
25	835707780

[6, 50, 24, 192, 550, 112, 512, 4044, 11282, 974, 1126, 17716, 174292, 612204, 9928, 2146, 56080, 1549398, 36461174, 65533922, 197152, 3760, 150166, 6839146, 835707780]

cp's OEIS Frontend

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.

Table of values

List of values