A210698 - cp's OEIS frontend

A210698 Number of 2 X 2 matrices having all terms in {1,...,n} and determinant = 0 (mod 3).

n	a(n)
1	1
2	8
3	33
4	90
5	209
6	528
7	889
8	1432
9	2673
10	3802
11	5297
12	8448
13	11025
14	14216
15	20625
16	25546
17	31393
18	42768
19	51145
20	60824
21	79233
22	92394
23	107297
24	135168
25	154657
26	176392
27	216513
28	244090
29	274481
30	330000
31	367641
32	408728
33	483153
34	533050
35	587089

[1, 8, 33, 90, 209, 528, 889, 1432, 2673, 3802, 5297, 8448, 11025, 14216, 20625, 25546, 31393, 42768, 51145, 60824, 79233, 92394, 107297, 135168, 154657, 176392, 216513, 244090, 274481, 330000, 367641, 408728, 483153, 533050, 587089]

cp's OEIS Frontend

A210698 Number of 2 X 2 matrices having all terms in {1,...,n} and determinant = 0 (mod 3).

Table of values

List of values