A187706 - cp's OEIS frontend

A187706 Number of 3X3 0..n arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal.

n	a(n)
1	128
2	1489
3	8272
4	31461
5	93476
6	235773
7	524284
8	1062857
9	1999212
10	3541677
11	5967404
12	9648841
13	15048584
14	22766353
15	33534080
16	48248321
17	67983232
18	94042589
19	127929948
20	171449249
21	226655576
22	295941137
23	382036240
24	488090685
25	617595596
26	774557293

[128, 1489, 8272, 31461, 93476, 235773, 524284, 1062857, 1999212, 3541677, 5967404, 9648841, 15048584, 22766353, 33534080, 48248321, 67983232, 94042589, 127929948, 171449249, 226655576, 295941137, 382036240, 488090685, 617595596, 774557293]

cp's OEIS Frontend

A187706 Number of 3X3 0..n arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal.

Table of values

List of values