A385871 - cp's OEIS frontend

A385871 a(n) is the number of primes in the prime chain to which prime(n) belongs. Details are in the Comments.

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

[3, 3, 3, 3, 3, 1, 1, 2, 3, 2, 1, 2, 2, 1, 3, 2, 1, 1, 1, 1, 2, 2, 3, 1, 2, 2, 2, 2, 1, 1, 1, 2, 3, 1, 3, 1, 2, 2, 2, 2, 2, 4, 1, 1, 1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 2, 4, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 2, 1, 1, 3, 2]

cp's OEIS Frontend

A385871 a(n) is the number of primes in the prime chain to which prime(n) belongs. Details are in the Comments.

Table of values

List of values

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

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

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