A066088 - cp's OEIS frontend

A066088 Number of distinct prime factors of sigma_2(n), where sigma_2(n) = A001157(n).

n	a(n)
1	0
2	1
3	2
4	2
5	2
6	2
7	2
8	2
9	2
10	3
11	2
12	4
13	3
14	2
15	3
16	2
17	3
18	3
19	2
20	4
21	2
22	3
23	3
24	3
25	3
26	3
27	3
28	4
29	2
30	3
31	3
32	4
33	3
34	3
35	3
36	3
37	3
38	3
39	3
40	4
41	2
42	2
43	3
44	4
45	3
46	3
47	4
48	4
49	3
50	4
51	3
52	5
53	3
54	3
55	3
56	3
57	3
58	3
59	2
60	5
61	2
62	4
63	4
64	2
65	4
66	3
67	3
68	5
69	3
70	3
71	2
72	4
73	4
74	3
75	5
76	4
77	3
78	3
79	2
80	4
81	2
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	3
90	4
91	3
92	5
93	4
94	4
95	3
96	5
97	3
98	4
99	4
100	3
101	2
102	3
103	3
104	3
105	3

[0, 1, 2, 2, 2, 2, 2, 2, 2, 3, 2, 4, 3, 2, 3, 2, 3, 3, 2, 4, 2, 3, 3, 3, 3, 3, 3, 4, 2, 3, 3, 4, 3, 3, 3, 3, 3, 3, 3, 4, 2, 2, 3, 4, 3, 3, 4, 4, 3, 4, 3, 5, 3, 3, 3, 3, 3, 3, 2, 5, 2, 4, 4, 2, 4, 3, 3, 5, 3, 3, 2, 4, 4, 3, 5, 4, 3, 3, 2, 4, 2, 3, 4, 4, 4, 3, 3, 4, 3, 4, 3, 5, 4, 4, 3, 5, 3, 4, 4, 3, 2, 3, 3, 3, 3]

cp's OEIS Frontend

A066088 Number of distinct prime factors of sigma_2(n), where sigma_2(n) = A001157(n).

Table of values

List of values

n	a(n)
1	0
2	1
3	2
4	2
5	2
6	2
7	2
8	2
9	2
10	3
11	2
12	4
13	3
14	2
15	3
16	2
17	3
18	3
19	2
20	4
21	2
22	3
23	3
24	3
25	3
26	3
27	3
28	4
29	2
30	3
31	3
32	4
33	3
34	3
35	3
36	3
37	3
38	3
39	3
40	4
41	2
42	2
43	3
44	4
45	3
46	3
47	4
48	4
49	3
50	4
51	3
52	5
53	3
54	3
55	3
56	3
57	3
58	3
59	2
60	5
61	2
62	4
63	4
64	2
65	4
66	3
67	3
68	5
69	3
70	3
71	2
72	4
73	4
74	3
75	5
76	4
77	3
78	3
79	2
80	4
81	2
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	3
90	4
91	3
92	5
93	4
94	4
95	3
96	5
97	3
98	4
99	4
100	3
101	2
102	3
103	3
104	3
105	3

n	a(n)
1	0
2	1
3	2
4	2
5	2
6	2
7	2
8	2
9	2
10	3
11	2
12	4
13	3
14	2
15	3
16	2
17	3
18	3
19	2
20	4
21	2
22	3
23	3
24	3
25	3
26	3
27	3
28	4
29	2
30	3
31	3
32	4
33	3
34	3
35	3
36	3
37	3
38	3
39	3
40	4
41	2
42	2
43	3
44	4
45	3
46	3
47	4
48	4
49	3
50	4
51	3
52	5
53	3
54	3
55	3
56	3
57	3
58	3
59	2
60	5
61	2
62	4
63	4
64	2
65	4
66	3
67	3
68	5
69	3
70	3
71	2
72	4
73	4
74	3
75	5
76	4
77	3
78	3
79	2
80	4
81	2
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	3
90	4
91	3
92	5
93	4
94	4
95	3
96	5
97	3
98	4
99	4
100	3
101	2
102	3
103	3
104	3
105	3

n	a(n)
1	0
2	1
3	2
4	2
5	2
6	2
7	2
8	2
9	2
10	3
11	2
12	4
13	3
14	2
15	3
16	2
17	3
18	3
19	2
20	4
21	2
22	3
23	3
24	3
25	3
26	3
27	3
28	4
29	2
30	3
31	3
32	4
33	3
34	3
35	3
36	3
37	3
38	3
39	3
40	4
41	2
42	2
43	3
44	4
45	3
46	3
47	4
48	4
49	3
50	4
51	3
52	5
53	3
54	3
55	3
56	3
57	3
58	3
59	2
60	5
61	2
62	4
63	4
64	2
65	4
66	3
67	3
68	5
69	3
70	3
71	2
72	4
73	4
74	3
75	5
76	4
77	3
78	3
79	2
80	4
81	2
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	3
90	4
91	3
92	5
93	4
94	4
95	3
96	5
97	3
98	4
99	4
100	3
101	2
102	3
103	3
104	3
105	3