A326146 - cp's OEIS frontend

A326146 a(n) = sigma(n) - A020639(n) - n, where A020639 gives the smallest prime factor of n, and sigma is the sum of divisors of n.

n	a(n)
1	-1
2	-1
3	-2
4	1
5	-4
6	4
7	-6
8	5
9	1
10	6
11	-10
12	14
13	-12
14	8
15	6
16	13
17	-16
18	19
19	-18
20	20
21	8
22	12
23	-22
24	34
25	1
26	14
27	10
28	26
29	-28
30	40
31	-30
32	29
33	12
34	18
35	8
36	53
37	-36
38	20
39	14
40	48
41	-40
42	52
43	-42
44	38
45	30
46	24
47	-46
48	74
49	1
50	41
51	18
52	44
53	-52
54	64
55	12
56	62
57	20
58	30
59	-58
60	106
61	-60
62	32
63	38
64	61
65	14
66	76
67	-66
68	56
69	24
70	72
71	-70
72	121
73	-72
74	38
75	46
76	62
77	12
78	88

[-1, -1, -2, 1, -4, 4, -6, 5, 1, 6, -10, 14, -12, 8, 6, 13, -16, 19, -18, 20, 8, 12, -22, 34, 1, 14, 10, 26, -28, 40, -30, 29, 12, 18, 8, 53, -36, 20, 14, 48, -40, 52, -42, 38, 30, 24, -46, 74, 1, 41, 18, 44, -52, 64, 12, 62, 20, 30, -58, 106, -60, 32, 38, 61, 14, 76, -66, 56, 24, 72, -70, 121, -72, 38, 46, 62, 12, 88]

cp's OEIS Frontend

A326146 a(n) = sigma(n) - A020639(n) - n, where A020639 gives the smallest prime factor of n, and sigma is the sum of divisors of n.

Table of values

List of values

n	a(n)
1	-1
2	-1
3	-2
4	1
5	-4
6	4
7	-6
8	5
9	1
10	6
11	-10
12	14
13	-12
14	8
15	6
16	13
17	-16
18	19
19	-18
20	20
21	8
22	12
23	-22
24	34
25	1
26	14
27	10
28	26
29	-28
30	40
31	-30
32	29
33	12
34	18
35	8
36	53
37	-36
38	20
39	14
40	48
41	-40
42	52
43	-42
44	38
45	30
46	24
47	-46
48	74
49	1
50	41
51	18
52	44
53	-52
54	64
55	12
56	62
57	20
58	30
59	-58
60	106
61	-60
62	32
63	38
64	61
65	14
66	76
67	-66
68	56
69	24
70	72
71	-70
72	121
73	-72
74	38
75	46
76	62
77	12
78	88

n	a(n)
1	-1
2	-1
3	-2
4	1
5	-4
6	4
7	-6
8	5
9	1
10	6
11	-10
12	14
13	-12
14	8
15	6
16	13
17	-16
18	19
19	-18
20	20
21	8
22	12
23	-22
24	34
25	1
26	14
27	10
28	26
29	-28
30	40
31	-30
32	29
33	12
34	18
35	8
36	53
37	-36
38	20
39	14
40	48
41	-40
42	52
43	-42
44	38
45	30
46	24
47	-46
48	74
49	1
50	41
51	18
52	44
53	-52
54	64
55	12
56	62
57	20
58	30
59	-58
60	106
61	-60
62	32
63	38
64	61
65	14
66	76
67	-66
68	56
69	24
70	72
71	-70
72	121
73	-72
74	38
75	46
76	62
77	12
78	88

n	a(n)
1	-1
2	-1
3	-2
4	1
5	-4
6	4
7	-6
8	5
9	1
10	6
11	-10
12	14
13	-12
14	8
15	6
16	13
17	-16
18	19
19	-18
20	20
21	8
22	12
23	-22
24	34
25	1
26	14
27	10
28	26
29	-28
30	40
31	-30
32	29
33	12
34	18
35	8
36	53
37	-36
38	20
39	14
40	48
41	-40
42	52
43	-42
44	38
45	30
46	24
47	-46
48	74
49	1
50	41
51	18
52	44
53	-52
54	64
55	12
56	62
57	20
58	30
59	-58
60	106
61	-60
62	32
63	38
64	61
65	14
66	76
67	-66
68	56
69	24
70	72
71	-70
72	121
73	-72
74	38
75	46
76	62
77	12
78	88