A382811 - cp's OEIS frontend

A382811 Integers k such that d*2^k - 1 is prime for some divisor d of k.

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	10
8	12
9	13
10	16
11	17
12	18
13	19
14	21
15	28
16	30
17	31
18	36
19	42
20	46
21	54
22	60
23	61
24	63
25	75
26	81
27	88
28	89
29	99
30	102
31	104
32	106
33	107
34	108
35	115
36	123
37	126
38	127
39	132
40	133
41	204
42	214
43	216
44	225
45	249
46	264
47	270
48	286
49	304
50	306
51	324
52	330
53	342
54	352
55	362
56	384
57	390

[2, 3, 4, 5, 6, 7, 10, 12, 13, 16, 17, 18, 19, 21, 28, 30, 31, 36, 42, 46, 54, 60, 61, 63, 75, 81, 88, 89, 99, 102, 104, 106, 107, 108, 115, 123, 126, 127, 132, 133, 204, 214, 216, 225, 249, 264, 270, 286, 304, 306, 324, 330, 342, 352, 362, 384, 390]

cp's OEIS Frontend

A382811 Integers k such that d*2^k - 1 is prime for some divisor d of k.

Table of values

List of values

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	10
8	12
9	13
10	16
11	17
12	18
13	19
14	21
15	28
16	30
17	31
18	36
19	42
20	46
21	54
22	60
23	61
24	63
25	75
26	81
27	88
28	89
29	99
30	102
31	104
32	106
33	107
34	108
35	115
36	123
37	126
38	127
39	132
40	133
41	204
42	214
43	216
44	225
45	249
46	264
47	270
48	286
49	304
50	306
51	324
52	330
53	342
54	352
55	362
56	384
57	390

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	10
8	12
9	13
10	16
11	17
12	18
13	19
14	21
15	28
16	30
17	31
18	36
19	42
20	46
21	54
22	60
23	61
24	63
25	75
26	81
27	88
28	89
29	99
30	102
31	104
32	106
33	107
34	108
35	115
36	123
37	126
38	127
39	132
40	133
41	204
42	214
43	216
44	225
45	249
46	264
47	270
48	286
49	304
50	306
51	324
52	330
53	342
54	352
55	362
56	384
57	390

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	10
8	12
9	13
10	16
11	17
12	18
13	19
14	21
15	28
16	30
17	31
18	36
19	42
20	46
21	54
22	60
23	61
24	63
25	75
26	81
27	88
28	89
29	99
30	102
31	104
32	106
33	107
34	108
35	115
36	123
37	126
38	127
39	132
40	133
41	204
42	214
43	216
44	225
45	249
46	264
47	270
48	286
49	304
50	306
51	324
52	330
53	342
54	352
55	362
56	384
57	390