A058977 - cp's OEIS frontend

A058977 For a rational number p/q let f(p/q) = sum of distinct prime factors (A008472) of p+q divided by number of distinct prime factors (A001221) of p+q; a(n) is obtained by iterating f, starting at n/1, until an integer is reached, or if no integer is ever reached then a(n) = 0.

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

[2, 3, 2, 5, 7, 7, 2, 3, 3, 11, 7, 13, 11, 4, 2, 17, 7, 19, 3, 5, 4, 23, 7, 5, 17, 3, 11, 29, 13, 31, 2, 7, 5, 6, 7, 37, 23, 8, 3, 41, 4, 43, 4, 4, 3, 47, 7, 7, 3, 10, 17, 53, 7, 8, 11, 11, 7, 59, 13, 61, 6, 5, 2, 9, 19, 67, 5, 13, 17, 71, 7, 73, 41, 4, 23, 9, 6, 79, 3, 3, 4, 83, 4, 11, 47]

cp's OEIS Frontend

A058977 For a rational number p/q let f(p/q) = sum of distinct prime factors (A008472) of p+q divided by number of distinct prime factors (A001221) of p+q; a(n) is obtained by iterating f, starting at n/1, until an integer is reached, or if no integer is ever reached then a(n) = 0.

Table of values

List of values

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

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

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