A334490 - cp's OEIS frontend

A334490 a(n) = Sum_{d|n} gcd(d, sigma(d)).

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

[1, 2, 2, 3, 2, 9, 2, 4, 3, 5, 2, 14, 2, 5, 6, 5, 2, 13, 2, 8, 4, 5, 2, 27, 3, 5, 4, 34, 2, 21, 2, 6, 6, 5, 4, 19, 2, 5, 4, 19, 2, 19, 2, 10, 10, 5, 2, 32, 3, 7, 6, 8, 2, 20, 4, 43, 4, 5, 2, 40, 2, 5, 6, 7, 4, 21, 2, 8, 6, 11, 2, 35, 2, 5, 8, 10, 4, 19, 2, 22]

cp's OEIS Frontend

A334490 a(n) = Sum_{d|n} gcd(d, sigma(d)).

Table of values

List of values

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

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

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