A102347 - cp's OEIS frontend

A102347 Number of distinct prime factors of 10^n - 1.

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	3
8	5
9	3
10	5
11	3
12	7
13	4
14	5
15	6
16	7
17	3
18	8
19	2
20	8
21	7
22	7
23	2
24	10
25	6
26	7
27	5
28	9
29	6
30	13
31	4
32	12
33	6
34	7
35	8
36	11
37	4
38	4
39	6
40	12
41	5
42	14
43	5
44	11
45	9
46	7
47	3
48	13
49	5
50	11
51	8
52	10
53	5
54	12
55	9
56	13
57	6
58	9
59	3
60	20
61	8
62	6
63	13
64	16
65	8
66	14
67	4
68	11
69	6
70	13
71	3
72	17
73	4
74	8
75	12
76	7
77	9
78	15
79	7
80	16
81	10
82	8
83	4
84	21
85	8
86	9
87	10
88	15
89	6
90	21
91	13

[1, 2, 2, 3, 3, 5, 3, 5, 3, 5, 3, 7, 4, 5, 6, 7, 3, 8, 2, 8, 7, 7, 2, 10, 6, 7, 5, 9, 6, 13, 4, 12, 6, 7, 8, 11, 4, 4, 6, 12, 5, 14, 5, 11, 9, 7, 3, 13, 5, 11, 8, 10, 5, 12, 9, 13, 6, 9, 3, 20, 8, 6, 13, 16, 8, 14, 4, 11, 6, 13, 3, 17, 4, 8, 12, 7, 9, 15, 7, 16, 10, 8, 4, 21, 8, 9, 10, 15, 6, 21, 13]

cp's OEIS Frontend

A102347 Number of distinct prime factors of 10^n - 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	3
8	5
9	3
10	5
11	3
12	7
13	4
14	5
15	6
16	7
17	3
18	8
19	2
20	8
21	7
22	7
23	2
24	10
25	6
26	7
27	5
28	9
29	6
30	13
31	4
32	12
33	6
34	7
35	8
36	11
37	4
38	4
39	6
40	12
41	5
42	14
43	5
44	11
45	9
46	7
47	3
48	13
49	5
50	11
51	8
52	10
53	5
54	12
55	9
56	13
57	6
58	9
59	3
60	20
61	8
62	6
63	13
64	16
65	8
66	14
67	4
68	11
69	6
70	13
71	3
72	17
73	4
74	8
75	12
76	7
77	9
78	15
79	7
80	16
81	10
82	8
83	4
84	21
85	8
86	9
87	10
88	15
89	6
90	21
91	13

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	3
8	5
9	3
10	5
11	3
12	7
13	4
14	5
15	6
16	7
17	3
18	8
19	2
20	8
21	7
22	7
23	2
24	10
25	6
26	7
27	5
28	9
29	6
30	13
31	4
32	12
33	6
34	7
35	8
36	11
37	4
38	4
39	6
40	12
41	5
42	14
43	5
44	11
45	9
46	7
47	3
48	13
49	5
50	11
51	8
52	10
53	5
54	12
55	9
56	13
57	6
58	9
59	3
60	20
61	8
62	6
63	13
64	16
65	8
66	14
67	4
68	11
69	6
70	13
71	3
72	17
73	4
74	8
75	12
76	7
77	9
78	15
79	7
80	16
81	10
82	8
83	4
84	21
85	8
86	9
87	10
88	15
89	6
90	21
91	13

n	a(n)
1	1
2	2
3	2
4	3
5	3
6	5
7	3
8	5
9	3
10	5
11	3
12	7
13	4
14	5
15	6
16	7
17	3
18	8
19	2
20	8
21	7
22	7
23	2
24	10
25	6
26	7
27	5
28	9
29	6
30	13
31	4
32	12
33	6
34	7
35	8
36	11
37	4
38	4
39	6
40	12
41	5
42	14
43	5
44	11
45	9
46	7
47	3
48	13
49	5
50	11
51	8
52	10
53	5
54	12
55	9
56	13
57	6
58	9
59	3
60	20
61	8
62	6
63	13
64	16
65	8
66	14
67	4
68	11
69	6
70	13
71	3
72	17
73	4
74	8
75	12
76	7
77	9
78	15
79	7
80	16
81	10
82	8
83	4
84	21
85	8
86	9
87	10
88	15
89	6
90	21
91	13