A215136 - cp's OEIS frontend

A215136 Start with n, iterate the process x -> x*3-1 until reaching a prime; then a(n) is the number of iterations required, or 0 if no prime is ever reached.

n	a(n)
1	1
2	1
3	2
4	1
5	2
6	1
7	2
8	1
9	6
10	1
11	8
12	3
13	2
14	1
15	2
16	1
17	2
18	1
19	2
20	1
21	4892
22	47
23	4
24	1
25	10
26	5
27	2
28	1
29	2
30	1
31	44
32	7
33	2
34	1
35	2
36	1
37	4
38	1
39	2
40	9
41	12
42	11
43	2
44	1
45	2
46	1
47	2
48	3
49	4
50	1
51	4
52	367
53	4
54	5
55	2
56	1
57	2
58	1
59	12
60	1
61	12
62	4891
63	2
64	1
65	46
66	1
67	2
68	3
69	2
70	3
71	4
72	3
73	2
74	9
75	6
76	1
77	4
78	1
79	4
80	1
81	4
82	27

[1, 1, 2, 1, 2, 1, 2, 1, 6, 1, 8, 3, 2, 1, 2, 1, 2, 1, 2, 1, 4892, 47, 4, 1, 10, 5, 2, 1, 2, 1, 44, 7, 2, 1, 2, 1, 4, 1, 2, 9, 12, 11, 2, 1, 2, 1, 2, 3, 4, 1, 4, 367, 4, 5, 2, 1, 2, 1, 12, 1, 12, 4891, 2, 1, 46, 1, 2, 3, 2, 3, 4, 3, 2, 9, 6, 1, 4, 1, 4, 1, 4, 27]

cp's OEIS Frontend

A215136 Start with n, iterate the process x -> x*3-1 until reaching a prime; then a(n) is the number of iterations required, or 0 if no prime is ever reached.

Table of values

List of values