A373801 - cp's OEIS frontend

A373801 a(1) = 2; thereafter, if a(n-1) is prime then a(n) = prime(n) + 1; otherwise a(n) = 2*a(n-1) - 1.

n	a(n)
1	2
2	4
3	7
4	8
5	15
6	29
7	18
8	35
9	69
10	137
11	32
12	63
13	125
14	249
15	497
16	993
17	1985
18	3969
19	7937
20	72
21	143
22	285
23	569
24	90
25	179
26	102
27	203
28	405
29	809
30	114
31	227
32	132
33	263
34	140
35	279
36	557
37	158
38	315
39	629
40	1257
41	2513
42	5025
43	10049
44	20097
45	40193
46	200
47	399
48	797
49	228
50	455
51	909
52	1817
53	3633
54	7265
55	14529
56	29057
57	58113
58	116225

[2, 4, 7, 8, 15, 29, 18, 35, 69, 137, 32, 63, 125, 249, 497, 993, 1985, 3969, 7937, 72, 143, 285, 569, 90, 179, 102, 203, 405, 809, 114, 227, 132, 263, 140, 279, 557, 158, 315, 629, 1257, 2513, 5025, 10049, 20097, 40193, 200, 399, 797, 228, 455, 909, 1817, 3633, 7265, 14529, 29057, 58113, 116225]

cp's OEIS Frontend

A373801 a(1) = 2; thereafter, if a(n-1) is prime then a(n) = prime(n) + 1; otherwise a(n) = 2*a(n-1) - 1.

Table of values

List of values