A178151 - cp's OEIS frontend

A178151 The number of quadratic residues (mod p) less than p/2, where p=prime(n).

n	a(n)
2	1
3	1
4	2
5	4
6	3
7	4
8	6
9	7
10	7
11	9
12	9
13	10
14	12
15	14
16	13
17	19
18	15
19	18
20	21
21	18
22	22
23	25
24	22
25	24
26	25
27	28
28	31
29	27
30	28
31	34
32	40
33	34
34	39
35	37
36	41
37	39
38	42
39	47
40	43
41	52
42	45
43	54
44	48
45	49
46	54
47	57
48	59
49	64
50	57
51	58
52	67
53	60
54	73
55	64
56	72
57	67
58	73
59	69
60	70
61	75
62	73
63	81
64	87
65	78
66	79
67	87
68	84
69	94
70	87
71	88
72	99
73	96
74	93

[1, 1, 2, 4, 3, 4, 6, 7, 7, 9, 9, 10, 12, 14, 13, 19, 15, 18, 21, 18, 22, 25, 22, 24, 25, 28, 31, 27, 28, 34, 40, 34, 39, 37, 41, 39, 42, 47, 43, 52, 45, 54, 48, 49, 54, 57, 59, 64, 57, 58, 67, 60, 73, 64, 72, 67, 73, 69, 70, 75, 73, 81, 87, 78, 79, 87, 84, 94, 87, 88, 99, 96, 93]

cp's OEIS Frontend

A178151 The number of quadratic residues (mod p) less than p/2, where p=prime(n).

Table of values

List of values

n	a(n)
2	1
3	1
4	2
5	4
6	3
7	4
8	6
9	7
10	7
11	9
12	9
13	10
14	12
15	14
16	13
17	19
18	15
19	18
20	21
21	18
22	22
23	25
24	22
25	24
26	25
27	28
28	31
29	27
30	28
31	34
32	40
33	34
34	39
35	37
36	41
37	39
38	42
39	47
40	43
41	52
42	45
43	54
44	48
45	49
46	54
47	57
48	59
49	64
50	57
51	58
52	67
53	60
54	73
55	64
56	72
57	67
58	73
59	69
60	70
61	75
62	73
63	81
64	87
65	78
66	79
67	87
68	84
69	94
70	87
71	88
72	99
73	96
74	93

n	a(n)
2	1
3	1
4	2
5	4
6	3
7	4
8	6
9	7
10	7
11	9
12	9
13	10
14	12
15	14
16	13
17	19
18	15
19	18
20	21
21	18
22	22
23	25
24	22
25	24
26	25
27	28
28	31
29	27
30	28
31	34
32	40
33	34
34	39
35	37
36	41
37	39
38	42
39	47
40	43
41	52
42	45
43	54
44	48
45	49
46	54
47	57
48	59
49	64
50	57
51	58
52	67
53	60
54	73
55	64
56	72
57	67
58	73
59	69
60	70
61	75
62	73
63	81
64	87
65	78
66	79
67	87
68	84
69	94
70	87
71	88
72	99
73	96
74	93

n	a(n)
2	1
3	1
4	2
5	4
6	3
7	4
8	6
9	7
10	7
11	9
12	9
13	10
14	12
15	14
16	13
17	19
18	15
19	18
20	21
21	18
22	22
23	25
24	22
25	24
26	25
27	28
28	31
29	27
30	28
31	34
32	40
33	34
34	39
35	37
36	41
37	39
38	42
39	47
40	43
41	52
42	45
43	54
44	48
45	49
46	54
47	57
48	59
49	64
50	57
51	58
52	67
53	60
54	73
55	64
56	72
57	67
58	73
59	69
60	70
61	75
62	73
63	81
64	87
65	78
66	79
67	87
68	84
69	94
70	87
71	88
72	99
73	96
74	93