A383043 - cp's OEIS frontend

A383043 Integers k such that d*2^k - 1 is prime for some proper 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	88
27	89
28	99
29	102
30	104
31	106
32	107
33	108
34	126
35	127
36	132
37	133
38	204
39	214
40	216
41	225
42	264
43	270
44	286
45	304
46	306
47	324
48	330
49	342
50	352
51	390
52	414
53	420
54	456
55	462
56	468

[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, 88, 89, 99, 102, 104, 106, 107, 108, 126, 127, 132, 133, 204, 214, 216, 225, 264, 270, 286, 304, 306, 324, 330, 342, 352, 390, 414, 420, 456, 462, 468]

cp's OEIS Frontend

A383043 Integers k such that d*2^k - 1 is prime for some proper 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	88
27	89
28	99
29	102
30	104
31	106
32	107
33	108
34	126
35	127
36	132
37	133
38	204
39	214
40	216
41	225
42	264
43	270
44	286
45	304
46	306
47	324
48	330
49	342
50	352
51	390
52	414
53	420
54	456
55	462
56	468

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	88
27	89
28	99
29	102
30	104
31	106
32	107
33	108
34	126
35	127
36	132
37	133
38	204
39	214
40	216
41	225
42	264
43	270
44	286
45	304
46	306
47	324
48	330
49	342
50	352
51	390
52	414
53	420
54	456
55	462
56	468

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	88
27	89
28	99
29	102
30	104
31	106
32	107
33	108
34	126
35	127
36	132
37	133
38	204
39	214
40	216
41	225
42	264
43	270
44	286
45	304
46	306
47	324
48	330
49	342
50	352
51	390
52	414
53	420
54	456
55	462
56	468