A330691 - cp's OEIS frontend

A330691 a(n) = gcd(n, A309639(n)), where A309639(n) is the index of the least harmonic number H_i whose denominator (A002805) is divisible by n.

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

[1, 2, 3, 4, 5, 3, 7, 8, 9, 5, 11, 4, 13, 7, 5, 16, 17, 9, 19, 5, 3, 11, 23, 3, 25, 13, 27, 7, 29, 5, 31, 32, 11, 17, 7, 9, 37, 19, 13, 8, 41, 3, 43, 11, 9, 23, 47, 16, 49, 25, 17, 13, 53, 27, 11, 8, 19, 29, 59, 5, 61, 31, 9, 64, 13, 11, 67, 17, 3, 7, 71, 9, 73, 37, 25, 19, 11, 13, 79, 16, 81, 41, 83, 3, 17, 43, 29, 11, 89, 9]

cp's OEIS Frontend

A330691 a(n) = gcd(n, A309639(n)), where A309639(n) is the index of the least harmonic number H_i whose denominator (A002805) is divisible by n.

Table of values

List of values

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

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

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