A211066 - cp's OEIS frontend

A211066 Number of 2 X 2 matrices having all terms in {1,...,n} and nonnegative even determinant.

n	a(n)
1	1
2	8
3	28
4	96
5	193
6	448
7	728
8	1360
9	1985
10	3264
11	4420
12	6696
13	8641
14	12296
15	15360
16	20896
17	25361
18	33344
19	39636
20	50680
21	59289
22	74056
23	85376
24	104728
25	119377
26	144032
27	162588
28	193568
29	216585
30	254880
31	283096
32	329656
33	363881
34	419856
35	460804

[1, 8, 28, 96, 193, 448, 728, 1360, 1985, 3264, 4420, 6696, 8641, 12296, 15360, 20896, 25361, 33344, 39636, 50680, 59289, 74056, 85376, 104728, 119377, 144032, 162588, 193568, 216585, 254880, 283096, 329656, 363881, 419856, 460804]

cp's OEIS Frontend

A211066 Number of 2 X 2 matrices having all terms in {1,...,n} and nonnegative even determinant.

Table of values

List of values