A368580 - cp's OEIS frontend

A368580 a(n) = Sum_{d|n and d^2 <= n} (1 + [d^2 < n]) * (2*d - 1), where [.] denote the Iverson brackets.

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

[1, 2, 2, 5, 2, 8, 2, 8, 7, 8, 2, 18, 2, 8, 12, 15, 2, 18, 2, 22, 12, 8, 2, 32, 11, 8, 12, 22, 2, 36, 2, 22, 12, 8, 20, 43, 2, 8, 12, 40, 2, 40, 2, 22, 30, 8, 2, 54, 15, 26, 12, 22, 2, 40, 20, 48, 12, 8, 2, 72, 2, 8, 38, 37, 20, 40, 2, 22, 12, 52, 2, 84, 2, 8]

cp's OEIS Frontend

A368580 a(n) = Sum_{d|n and d^2 <= n} (1 + [d^2 < n]) * (2*d - 1), where [.] denote the Iverson brackets.

Table of values

List of values

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

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

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