A189657 - cp's OEIS frontend

A189657 Start with n, apply k->2k+1 until a semiprime is reached; sequence gives the semiprimes.

n	a(n)
0	15
1	95
2	15
3	9
4	95
5	55
6	15
7	35
8	39
9	21
10	95
11	25
12	55
13	119
14	511
15	33
16	35
17	303
18	39
19	335
20	87
21	91
22	95
23	49
24	51
25	215
26	55
27	57
28	119
29	123
30	511
31	65
32	543
33	69
34	143
35	295
36	303
37	77
38	159
39	327
40	335
41	85
42	87
43	5759
44	91
45	93
46	95
47	391
48	799
49	203
50	415
51	54271
52	215
53	219
54	111
55	3647
56	115

[15, 95, 15, 9, 95, 55, 15, 35, 39, 21, 95, 25, 55, 119, 511, 33, 35, 303, 39, 335, 87, 91, 95, 49, 51, 215, 55, 57, 119, 123, 511, 65, 543, 69, 143, 295, 303, 77, 159, 327, 335, 85, 87, 5759, 91, 93, 95, 391, 799, 203, 415, 54271, 215, 219, 111, 3647, 115]

cp's OEIS Frontend

A189657 Start with n, apply k->2k+1 until a semiprime is reached; sequence gives the semiprimes.

Table of values

List of values