A219693 - cp's OEIS frontend

A219693 The number of symmetric positive definite 2 X 2 matrices whose entries are integers of absolute value at most n.

n	a(n)
1	1
2	10
3	31
4	68
5	133
6	226
7	351
8	512
9	721
10	986
11	1303
12	1676
13	2125
14	2642
15	3231
16	3896
17	4665
18	5522
19	6479
20	7532
21	8701
22	9986
23	11383
24	12896
25	14553
26	16354
27	18287
28	20364
29	22605
30	24994
31	27543
32	30248
33	33145
34	36226
35	39479
36	42908
37	46557
38	50402
39	54439
40	58680

[1, 10, 31, 68, 133, 226, 351, 512, 721, 986, 1303, 1676, 2125, 2642, 3231, 3896, 4665, 5522, 6479, 7532, 8701, 9986, 11383, 12896, 14553, 16354, 18287, 20364, 22605, 24994, 27543, 30248, 33145, 36226, 39479, 42908, 46557, 50402, 54439, 58680]

cp's OEIS Frontend

A219693 The number of symmetric positive definite 2 X 2 matrices whose entries are integers of absolute value at most n.

Table of values

List of values