A219736 - cp's OEIS frontend

A219736 The number of 2 X 2 matrices with all eigenvalues real and whose entries are integers with absolute value at most n.

n	a(n)
1	67
2	477
3	1759
4	4729
5	10395
6	20141
7	35423
8	58225
9	90579
10	134813
11	193503
12	269785
13	366267
14	486925
15	635199
16	815105
17	1030371
18	1286221
19	1586447
20	1937033
21	2342379
22	2808221
23	3340239
24	3945361
25	4628467
26	5396781
27	6257039
28	7216457
29	8281579
30	9461805
31	10762495
32	12193873

[67, 477, 1759, 4729, 10395, 20141, 35423, 58225, 90579, 134813, 193503, 269785, 366267, 486925, 635199, 815105, 1030371, 1286221, 1586447, 1937033, 2342379, 2808221, 3340239, 3945361, 4628467, 5396781, 6257039, 7216457, 8281579, 9461805, 10762495, 12193873]

cp's OEIS Frontend

A219736 The number of 2 X 2 matrices with all eigenvalues real and whose entries are integers with absolute value at most n.

Table of values

List of values