A276121 - cp's OEIS frontend

A276121 Smallest odd integer k such that k*2^prime(n)-1 is a prime number.

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	1
7	1
8	1
9	13
10	7
11	1
12	21
13	15
14	3
15	31
16	147
17	45
18	1
19	43
20	73
21	15
22	69
23	91
24	1
25	51
26	81
27	3
28	1
29	9
30	85
31	1
32	55
33	169
34	225
35	109
36	145
37	15
38	103
39	615
40	69
41	259
42	69
43	63
44	45
45	285
46	471
47	9
48	255
49	169
50	489
51	69
52	273
53	427
54	43
55	391
56	169
57	201
58	21
59	159
60	181
61	103
62	15
63	339

[1, 1, 1, 1, 3, 1, 1, 1, 13, 7, 1, 21, 15, 3, 31, 147, 45, 1, 43, 73, 15, 69, 91, 1, 51, 81, 3, 1, 9, 85, 1, 55, 169, 225, 109, 145, 15, 103, 615, 69, 259, 69, 63, 45, 285, 471, 9, 255, 169, 489, 69, 273, 427, 43, 391, 169, 201, 21, 159, 181, 103, 15, 339]

cp's OEIS Frontend

A276121 Smallest odd integer k such that k*2^prime(n)-1 is a prime number.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	1
7	1
8	1
9	13
10	7
11	1
12	21
13	15
14	3
15	31
16	147
17	45
18	1
19	43
20	73
21	15
22	69
23	91
24	1
25	51
26	81
27	3
28	1
29	9
30	85
31	1
32	55
33	169
34	225
35	109
36	145
37	15
38	103
39	615
40	69
41	259
42	69
43	63
44	45
45	285
46	471
47	9
48	255
49	169
50	489
51	69
52	273
53	427
54	43
55	391
56	169
57	201
58	21
59	159
60	181
61	103
62	15
63	339

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	1
7	1
8	1
9	13
10	7
11	1
12	21
13	15
14	3
15	31
16	147
17	45
18	1
19	43
20	73
21	15
22	69
23	91
24	1
25	51
26	81
27	3
28	1
29	9
30	85
31	1
32	55
33	169
34	225
35	109
36	145
37	15
38	103
39	615
40	69
41	259
42	69
43	63
44	45
45	285
46	471
47	9
48	255
49	169
50	489
51	69
52	273
53	427
54	43
55	391
56	169
57	201
58	21
59	159
60	181
61	103
62	15
63	339

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	1
7	1
8	1
9	13
10	7
11	1
12	21
13	15
14	3
15	31
16	147
17	45
18	1
19	43
20	73
21	15
22	69
23	91
24	1
25	51
26	81
27	3
28	1
29	9
30	85
31	1
32	55
33	169
34	225
35	109
36	145
37	15
38	103
39	615
40	69
41	259
42	69
43	63
44	45
45	285
46	471
47	9
48	255
49	169
50	489
51	69
52	273
53	427
54	43
55	391
56	169
57	201
58	21
59	159
60	181
61	103
62	15
63	339