A165918 - cp's OEIS frontend

A165918 a(n) = number of squarefree quadratic non-residues of n.

n	a(n)
1	0
2	0
3	1
4	2
5	2
6	2
7	3
8	5
9	4
10	3
11	4
12	7
13	5
14	5
15	7
16	10
17	7
18	8
19	6
20	11
21	10
22	8
23	10
24	15
25	10
26	8
27	11
28	15
29	10
30	12
31	12
32	18
33	15
34	11
35	15
36	21
37	13
38	13
39	19
40	25
41	16
42	19
43	14
44	25
45	24
46	17
47	19
48	29
49	19
50	18
51	21
52	28
53	17
54	22
55	25
56	33
57	25
58	18
59	19
60	35
61	21
62	22
63	32
64	34
65	28
66	29
67	20
68	36
69	33
70	31
71	29
72	44
73	26
74	23

[0, 0, 1, 2, 2, 2, 3, 5, 4, 3, 4, 7, 5, 5, 7, 10, 7, 8, 6, 11, 10, 8, 10, 15, 10, 8, 11, 15, 10, 12, 12, 18, 15, 11, 15, 21, 13, 13, 19, 25, 16, 19, 14, 25, 24, 17, 19, 29, 19, 18, 21, 28, 17, 22, 25, 33, 25, 18, 19, 35, 21, 22, 32, 34, 28, 29, 20, 36, 33, 31, 29, 44, 26, 23]

cp's OEIS Frontend

A165918 a(n) = number of squarefree quadratic non-residues of n.

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	2
5	2
6	2
7	3
8	5
9	4
10	3
11	4
12	7
13	5
14	5
15	7
16	10
17	7
18	8
19	6
20	11
21	10
22	8
23	10
24	15
25	10
26	8
27	11
28	15
29	10
30	12
31	12
32	18
33	15
34	11
35	15
36	21
37	13
38	13
39	19
40	25
41	16
42	19
43	14
44	25
45	24
46	17
47	19
48	29
49	19
50	18
51	21
52	28
53	17
54	22
55	25
56	33
57	25
58	18
59	19
60	35
61	21
62	22
63	32
64	34
65	28
66	29
67	20
68	36
69	33
70	31
71	29
72	44
73	26
74	23

n	a(n)
1	0
2	0
3	1
4	2
5	2
6	2
7	3
8	5
9	4
10	3
11	4
12	7
13	5
14	5
15	7
16	10
17	7
18	8
19	6
20	11
21	10
22	8
23	10
24	15
25	10
26	8
27	11
28	15
29	10
30	12
31	12
32	18
33	15
34	11
35	15
36	21
37	13
38	13
39	19
40	25
41	16
42	19
43	14
44	25
45	24
46	17
47	19
48	29
49	19
50	18
51	21
52	28
53	17
54	22
55	25
56	33
57	25
58	18
59	19
60	35
61	21
62	22
63	32
64	34
65	28
66	29
67	20
68	36
69	33
70	31
71	29
72	44
73	26
74	23

n	a(n)
1	0
2	0
3	1
4	2
5	2
6	2
7	3
8	5
9	4
10	3
11	4
12	7
13	5
14	5
15	7
16	10
17	7
18	8
19	6
20	11
21	10
22	8
23	10
24	15
25	10
26	8
27	11
28	15
29	10
30	12
31	12
32	18
33	15
34	11
35	15
36	21
37	13
38	13
39	19
40	25
41	16
42	19
43	14
44	25
45	24
46	17
47	19
48	29
49	19
50	18
51	21
52	28
53	17
54	22
55	25
56	33
57	25
58	18
59	19
60	35
61	21
62	22
63	32
64	34
65	28
66	29
67	20
68	36
69	33
70	31
71	29
72	44
73	26
74	23