A219744 - cp's OEIS frontend

A219744 The number of 2 X 2 symmetric positive definite matrices whose entries are integers x,y,z satisfying x^2 + y^2 + z^2 <= n^2.

n	a(n)
1	0
2	1
3	10
4	22
5	49
6	92
7	150
8	227
9	328
10	449
11	609
12	792
13	1017
14	1281
15	1582
16	1911
17	2308
18	2750
19	3241
20	3778
21	4420
22	5049
23	5776
24	6572
25	7429
26	8378
27	9413
28	10505
29	11646
30	12935
31	14251
32	15690
33	17235
34	18854
35	20580
36	22391
37	24330
38	26352
39	28541
40	30750

[0, 1, 10, 22, 49, 92, 150, 227, 328, 449, 609, 792, 1017, 1281, 1582, 1911, 2308, 2750, 3241, 3778, 4420, 5049, 5776, 6572, 7429, 8378, 9413, 10505, 11646, 12935, 14251, 15690, 17235, 18854, 20580, 22391, 24330, 26352, 28541, 30750]

cp's OEIS Frontend

A219744 The number of 2 X 2 symmetric positive definite matrices whose entries are integers x,y,z satisfying x^2 + y^2 + z^2 <= n^2.

Table of values

List of values