A211071 - cp's OEIS frontend

A211071 Number of 2 X 2 matrices having all terms in {1,...,n} and determinant = 1 (mod 3).

n	a(n)
1	0
2	4
3	24
4	83
5	208
6	384
7	756
8	1332
9	1944
10	3099
11	4672
12	6144
13	8768
14	12100
15	15000
16	19995
17	26064
18	31104
19	39588
20	49588
21	57624
22	70931
23	86272
24	98304
25	117984
26	140292
27	157464
28	185283
29	216400
30	240000
31	277940
32	319924
33	351384
34	401643
35	456768

[0, 4, 24, 83, 208, 384, 756, 1332, 1944, 3099, 4672, 6144, 8768, 12100, 15000, 19995, 26064, 31104, 39588, 49588, 57624, 70931, 86272, 98304, 117984, 140292, 157464, 185283, 216400, 240000, 277940, 319924, 351384, 401643, 456768]

cp's OEIS Frontend

A211071 Number of 2 X 2 matrices having all terms in {1,...,n} and determinant = 1 (mod 3).

Table of values

List of values