A345001 - cp's OEIS frontend

A345001 a(n) = sigma(n) + n' - 2n, where n' is the arithmetic derivative of n (A003415) and sigma is the sum of divisors (A000203).

n	a(n)
1	-1
2	0
3	-1
4	3
5	-3
6	5
7	-5
8	11
9	1
10	5
11	-9
12	20
13	-11
14	5
15	2
16	31
17	-15
18	24
19	-17
20	26
21	0
22	5
23	-21
24	56
25	-9
26	5
27	13
28	32
29	-27
30	43
31	-29
32	79
33	-4
34	5
35	-10
36	79
37	-35
38	5
39	-6
40	78
41	-39
42	53
43	-41
44	44
45	27
46	5
47	-45
48	140
49	-27
50	38
51	-10
52	50
53	-51
54	93
55	-22
56	100
57	-12
58	5
59	-57
60	140
61	-59
62	5
63	29
64	191
65	-28
66	73
67	-65
68	62
69	-16
70	63
71	-69
72	207
73	-71
74	5
75	29
76	68

[-1, 0, -1, 3, -3, 5, -5, 11, 1, 5, -9, 20, -11, 5, 2, 31, -15, 24, -17, 26, 0, 5, -21, 56, -9, 5, 13, 32, -27, 43, -29, 79, -4, 5, -10, 79, -35, 5, -6, 78, -39, 53, -41, 44, 27, 5, -45, 140, -27, 38, -10, 50, -51, 93, -22, 100, -12, 5, -57, 140, -59, 5, 29, 191, -28, 73, -65, 62, -16, 63, -69, 207, -71, 5, 29, 68]

cp's OEIS Frontend

A345001 a(n) = sigma(n) + n' - 2n, where n' is the arithmetic derivative of n (A003415) and sigma is the sum of divisors (A000203).

Table of values

List of values

n	a(n)
1	-1
2	0
3	-1
4	3
5	-3
6	5
7	-5
8	11
9	1
10	5
11	-9
12	20
13	-11
14	5
15	2
16	31
17	-15
18	24
19	-17
20	26
21	0
22	5
23	-21
24	56
25	-9
26	5
27	13
28	32
29	-27
30	43
31	-29
32	79
33	-4
34	5
35	-10
36	79
37	-35
38	5
39	-6
40	78
41	-39
42	53
43	-41
44	44
45	27
46	5
47	-45
48	140
49	-27
50	38
51	-10
52	50
53	-51
54	93
55	-22
56	100
57	-12
58	5
59	-57
60	140
61	-59
62	5
63	29
64	191
65	-28
66	73
67	-65
68	62
69	-16
70	63
71	-69
72	207
73	-71
74	5
75	29
76	68

n	a(n)
1	-1
2	0
3	-1
4	3
5	-3
6	5
7	-5
8	11
9	1
10	5
11	-9
12	20
13	-11
14	5
15	2
16	31
17	-15
18	24
19	-17
20	26
21	0
22	5
23	-21
24	56
25	-9
26	5
27	13
28	32
29	-27
30	43
31	-29
32	79
33	-4
34	5
35	-10
36	79
37	-35
38	5
39	-6
40	78
41	-39
42	53
43	-41
44	44
45	27
46	5
47	-45
48	140
49	-27
50	38
51	-10
52	50
53	-51
54	93
55	-22
56	100
57	-12
58	5
59	-57
60	140
61	-59
62	5
63	29
64	191
65	-28
66	73
67	-65
68	62
69	-16
70	63
71	-69
72	207
73	-71
74	5
75	29
76	68

n	a(n)
1	-1
2	0
3	-1
4	3
5	-3
6	5
7	-5
8	11
9	1
10	5
11	-9
12	20
13	-11
14	5
15	2
16	31
17	-15
18	24
19	-17
20	26
21	0
22	5
23	-21
24	56
25	-9
26	5
27	13
28	32
29	-27
30	43
31	-29
32	79
33	-4
34	5
35	-10
36	79
37	-35
38	5
39	-6
40	78
41	-39
42	53
43	-41
44	44
45	27
46	5
47	-45
48	140
49	-27
50	38
51	-10
52	50
53	-51
54	93
55	-22
56	100
57	-12
58	5
59	-57
60	140
61	-59
62	5
63	29
64	191
65	-28
66	73
67	-65
68	62
69	-16
70	63
71	-69
72	207
73	-71
74	5
75	29
76	68