A209979 - cp's OEIS frontend

A209979 Number of unimodular 2 X 2 matrices having all elements in {1,2,...,n}.

n	a(n)
0	0
1	0
2	4
3	16
4	28
5	56
6	68
7	112
8	140
9	184
10	212
11	288
12	316
13	408
14	452
15	512
16	572
17	696
18	740
19	880
20	940
21	1032
22	1108
23	1280
24	1340
25	1496
26	1588
27	1728
28	1820
29	2040
30	2100
31	2336
32	2460
33	2616
34	2740
35	2928
36	3020
37	3304
38	3444
39	3632
40	3756
41	4072
42	4164
43	4496
44	4652
45	4840

[0, 0, 4, 16, 28, 56, 68, 112, 140, 184, 212, 288, 316, 408, 452, 512, 572, 696, 740, 880, 940, 1032, 1108, 1280, 1340, 1496, 1588, 1728, 1820, 2040, 2100, 2336, 2460, 2616, 2740, 2928, 3020, 3304, 3444, 3632, 3756, 4072, 4164, 4496, 4652, 4840]

cp's OEIS Frontend

A209979 Number of unimodular 2 X 2 matrices having all elements in {1,2,...,n}.

Table of values

List of values