A124316 - cp's OEIS frontend

A124316 a(n) = Sum_{d|n} sigma(gcd(d,n/d)), where sigma is the sum of divisors function, A000203.

n	a(n)
1	1
2	2
3	2
4	5
5	2
6	4
7	2
8	8
9	6
10	4
11	2
12	10
13	2
14	4
15	4
16	15
17	2
18	12
19	2
20	10
21	4
22	4
23	2
24	16
25	8
26	4
27	10
28	10
29	2
30	8
31	2
32	22
33	4
34	4
35	4
36	30
37	2
38	4
39	4
40	16
41	2
42	8
43	2
44	10
45	12
46	4
47	2
48	30
49	10
50	16
51	4
52	10
53	2
54	20
55	4
56	16
57	4
58	4
59	2
60	20
61	2
62	4
63	12
64	37
65	4
66	8
67	2
68	10
69	4
70	8
71	2
72	48
73	2
74	4
75	16
76	10
77	4
78	8
79	2
80	30
81	23
82	4
83	2
84	20
85	4
86	4
87	4
88	16
89	2
90	24

[1, 2, 2, 5, 2, 4, 2, 8, 6, 4, 2, 10, 2, 4, 4, 15, 2, 12, 2, 10, 4, 4, 2, 16, 8, 4, 10, 10, 2, 8, 2, 22, 4, 4, 4, 30, 2, 4, 4, 16, 2, 8, 2, 10, 12, 4, 2, 30, 10, 16, 4, 10, 2, 20, 4, 16, 4, 4, 2, 20, 2, 4, 12, 37, 4, 8, 2, 10, 4, 8, 2, 48, 2, 4, 16, 10, 4, 8, 2, 30, 23, 4, 2, 20, 4, 4, 4, 16, 2, 24]

cp's OEIS Frontend

A124316 a(n) = Sum_{d|n} sigma(gcd(d,n/d)), where sigma is the sum of divisors function, A000203.

Table of values

List of values

n	a(n)
1	1
2	2
3	2
4	5
5	2
6	4
7	2
8	8
9	6
10	4
11	2
12	10
13	2
14	4
15	4
16	15
17	2
18	12
19	2
20	10
21	4
22	4
23	2
24	16
25	8
26	4
27	10
28	10
29	2
30	8
31	2
32	22
33	4
34	4
35	4
36	30
37	2
38	4
39	4
40	16
41	2
42	8
43	2
44	10
45	12
46	4
47	2
48	30
49	10
50	16
51	4
52	10
53	2
54	20
55	4
56	16
57	4
58	4
59	2
60	20
61	2
62	4
63	12
64	37
65	4
66	8
67	2
68	10
69	4
70	8
71	2
72	48
73	2
74	4
75	16
76	10
77	4
78	8
79	2
80	30
81	23
82	4
83	2
84	20
85	4
86	4
87	4
88	16
89	2
90	24

n	a(n)
1	1
2	2
3	2
4	5
5	2
6	4
7	2
8	8
9	6
10	4
11	2
12	10
13	2
14	4
15	4
16	15
17	2
18	12
19	2
20	10
21	4
22	4
23	2
24	16
25	8
26	4
27	10
28	10
29	2
30	8
31	2
32	22
33	4
34	4
35	4
36	30
37	2
38	4
39	4
40	16
41	2
42	8
43	2
44	10
45	12
46	4
47	2
48	30
49	10
50	16
51	4
52	10
53	2
54	20
55	4
56	16
57	4
58	4
59	2
60	20
61	2
62	4
63	12
64	37
65	4
66	8
67	2
68	10
69	4
70	8
71	2
72	48
73	2
74	4
75	16
76	10
77	4
78	8
79	2
80	30
81	23
82	4
83	2
84	20
85	4
86	4
87	4
88	16
89	2
90	24

n	a(n)
1	1
2	2
3	2
4	5
5	2
6	4
7	2
8	8
9	6
10	4
11	2
12	10
13	2
14	4
15	4
16	15
17	2
18	12
19	2
20	10
21	4
22	4
23	2
24	16
25	8
26	4
27	10
28	10
29	2
30	8
31	2
32	22
33	4
34	4
35	4
36	30
37	2
38	4
39	4
40	16
41	2
42	8
43	2
44	10
45	12
46	4
47	2
48	30
49	10
50	16
51	4
52	10
53	2
54	20
55	4
56	16
57	4
58	4
59	2
60	20
61	2
62	4
63	12
64	37
65	4
66	8
67	2
68	10
69	4
70	8
71	2
72	48
73	2
74	4
75	16
76	10
77	4
78	8
79	2
80	30
81	23
82	4
83	2
84	20
85	4
86	4
87	4
88	16
89	2
90	24