A244963 - cp's OEIS frontend

A244963 a(n) = sigma(n) - n * Product_{p|n, p prime} (1 + 1/p).

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	0
7	0
8	3
9	1
10	0
11	0
12	4
13	0
14	0
15	0
16	7
17	0
18	3
19	0
20	6
21	0
22	0
23	0
24	12
25	1
26	0
27	4
28	8
29	0
30	0
31	0
32	15
33	0
34	0
35	0
36	19
37	0
38	0
39	0
40	18
41	0
42	0
43	0
44	12
45	6
46	0
47	0
48	28
49	1
50	3
51	0
52	14
53	0
54	12
55	0
56	24
57	0
58	0
59	0
60	24
61	0
62	0
63	8
64	31
65	0
66	0
67	0
68	18
69	0
70	0
71	0
72	51
73	0
74	0
75	4
76	20
77	0
78	0
79	0
80	42
81	13

[0, 0, 0, 1, 0, 0, 0, 3, 1, 0, 0, 4, 0, 0, 0, 7, 0, 3, 0, 6, 0, 0, 0, 12, 1, 0, 4, 8, 0, 0, 0, 15, 0, 0, 0, 19, 0, 0, 0, 18, 0, 0, 0, 12, 6, 0, 0, 28, 1, 3, 0, 14, 0, 12, 0, 24, 0, 0, 0, 24, 0, 0, 8, 31, 0, 0, 0, 18, 0, 0, 0, 51, 0, 0, 4, 20, 0, 0, 0, 42, 13]

cp's OEIS Frontend

A244963 a(n) = sigma(n) - n * Product_{p|n, p prime} (1 + 1/p).

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	0
7	0
8	3
9	1
10	0
11	0
12	4
13	0
14	0
15	0
16	7
17	0
18	3
19	0
20	6
21	0
22	0
23	0
24	12
25	1
26	0
27	4
28	8
29	0
30	0
31	0
32	15
33	0
34	0
35	0
36	19
37	0
38	0
39	0
40	18
41	0
42	0
43	0
44	12
45	6
46	0
47	0
48	28
49	1
50	3
51	0
52	14
53	0
54	12
55	0
56	24
57	0
58	0
59	0
60	24
61	0
62	0
63	8
64	31
65	0
66	0
67	0
68	18
69	0
70	0
71	0
72	51
73	0
74	0
75	4
76	20
77	0
78	0
79	0
80	42
81	13

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	0
7	0
8	3
9	1
10	0
11	0
12	4
13	0
14	0
15	0
16	7
17	0
18	3
19	0
20	6
21	0
22	0
23	0
24	12
25	1
26	0
27	4
28	8
29	0
30	0
31	0
32	15
33	0
34	0
35	0
36	19
37	0
38	0
39	0
40	18
41	0
42	0
43	0
44	12
45	6
46	0
47	0
48	28
49	1
50	3
51	0
52	14
53	0
54	12
55	0
56	24
57	0
58	0
59	0
60	24
61	0
62	0
63	8
64	31
65	0
66	0
67	0
68	18
69	0
70	0
71	0
72	51
73	0
74	0
75	4
76	20
77	0
78	0
79	0
80	42
81	13

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	0
7	0
8	3
9	1
10	0
11	0
12	4
13	0
14	0
15	0
16	7
17	0
18	3
19	0
20	6
21	0
22	0
23	0
24	12
25	1
26	0
27	4
28	8
29	0
30	0
31	0
32	15
33	0
34	0
35	0
36	19
37	0
38	0
39	0
40	18
41	0
42	0
43	0
44	12
45	6
46	0
47	0
48	28
49	1
50	3
51	0
52	14
53	0
54	12
55	0
56	24
57	0
58	0
59	0
60	24
61	0
62	0
63	8
64	31
65	0
66	0
67	0
68	18
69	0
70	0
71	0
72	51
73	0
74	0
75	4
76	20
77	0
78	0
79	0
80	42
81	13