A046522 - cp's OEIS frontend

A046522 a(n) = 2*floor(sqrt(n)) - d(n), where d(n) is the number of divisors of n (A000005).

n	a(n)
1	1
2	0
3	0
4	1
5	2
6	0
7	2
8	0
9	3
10	2
11	4
12	0
13	4
14	2
15	2
16	3
17	6
18	2
19	6
20	2
21	4
22	4
23	6
24	0
25	7
26	6
27	6
28	4
29	8
30	2
31	8
32	4
33	6
34	6
35	6
36	3
37	10
38	8
39	8
40	4
41	10
42	4
43	10
44	6
45	6
46	8
47	10
48	2
49	11
50	8
51	10
52	8
53	12
54	6
55	10
56	6
57	10
58	10
59	12
60	2
61	12
62	10
63	8
64	9
65	12
66	8
67	14
68	10
69	12
70	8
71	14
72	4
73	14
74	12
75	10
76	10
77	12
78	8
79	14
80	6

[1, 0, 0, 1, 2, 0, 2, 0, 3, 2, 4, 0, 4, 2, 2, 3, 6, 2, 6, 2, 4, 4, 6, 0, 7, 6, 6, 4, 8, 2, 8, 4, 6, 6, 6, 3, 10, 8, 8, 4, 10, 4, 10, 6, 6, 8, 10, 2, 11, 8, 10, 8, 12, 6, 10, 6, 10, 10, 12, 2, 12, 10, 8, 9, 12, 8, 14, 10, 12, 8, 14, 4, 14, 12, 10, 10, 12, 8, 14, 6]

cp's OEIS Frontend

A046522 a(n) = 2*floor(sqrt(n)) - d(n), where d(n) is the number of divisors of n (A000005).

Table of values

List of values

n	a(n)
1	1
2	0
3	0
4	1
5	2
6	0
7	2
8	0
9	3
10	2
11	4
12	0
13	4
14	2
15	2
16	3
17	6
18	2
19	6
20	2
21	4
22	4
23	6
24	0
25	7
26	6
27	6
28	4
29	8
30	2
31	8
32	4
33	6
34	6
35	6
36	3
37	10
38	8
39	8
40	4
41	10
42	4
43	10
44	6
45	6
46	8
47	10
48	2
49	11
50	8
51	10
52	8
53	12
54	6
55	10
56	6
57	10
58	10
59	12
60	2
61	12
62	10
63	8
64	9
65	12
66	8
67	14
68	10
69	12
70	8
71	14
72	4
73	14
74	12
75	10
76	10
77	12
78	8
79	14
80	6

n	a(n)
1	1
2	0
3	0
4	1
5	2
6	0
7	2
8	0
9	3
10	2
11	4
12	0
13	4
14	2
15	2
16	3
17	6
18	2
19	6
20	2
21	4
22	4
23	6
24	0
25	7
26	6
27	6
28	4
29	8
30	2
31	8
32	4
33	6
34	6
35	6
36	3
37	10
38	8
39	8
40	4
41	10
42	4
43	10
44	6
45	6
46	8
47	10
48	2
49	11
50	8
51	10
52	8
53	12
54	6
55	10
56	6
57	10
58	10
59	12
60	2
61	12
62	10
63	8
64	9
65	12
66	8
67	14
68	10
69	12
70	8
71	14
72	4
73	14
74	12
75	10
76	10
77	12
78	8
79	14
80	6

n	a(n)
1	1
2	0
3	0
4	1
5	2
6	0
7	2
8	0
9	3
10	2
11	4
12	0
13	4
14	2
15	2
16	3
17	6
18	2
19	6
20	2
21	4
22	4
23	6
24	0
25	7
26	6
27	6
28	4
29	8
30	2
31	8
32	4
33	6
34	6
35	6
36	3
37	10
38	8
39	8
40	4
41	10
42	4
43	10
44	6
45	6
46	8
47	10
48	2
49	11
50	8
51	10
52	8
53	12
54	6
55	10
56	6
57	10
58	10
59	12
60	2
61	12
62	10
63	8
64	9
65	12
66	8
67	14
68	10
69	12
70	8
71	14
72	4
73	14
74	12
75	10
76	10
77	12
78	8
79	14
80	6