A247479 - cp's OEIS frontend

A247479 Smallest odd k > 1 such that k*2^n+1 is a prime number.

n	a(n)
1	3
2	3
3	5
4	7
5	3
6	3
7	5
8	3
9	15
10	13
11	9
12	3
13	5
14	7
15	5
16	21
17	9
18	3
19	11
20	7
21	11
22	25
23	45
24	45
25	5
26	7
27	15
28	13
29	23
30	3
31	35
32	43
33	9
34	75
35	59
36	3
37	15
38	15
39	5
40	27
41	3
42	9
43	9
44	15
45	35
46	19
47	27
48	15
49	23
50	7
51	17
52	7
53	51
54	49
55	5
56	27
57	29
58	99
59	27
60	31
61	53
62	105
63	9
64	25
65	9
66	3
67	9
68	31
69	23

[3, 3, 5, 7, 3, 3, 5, 3, 15, 13, 9, 3, 5, 7, 5, 21, 9, 3, 11, 7, 11, 25, 45, 45, 5, 7, 15, 13, 23, 3, 35, 43, 9, 75, 59, 3, 15, 15, 5, 27, 3, 9, 9, 15, 35, 19, 27, 15, 23, 7, 17, 7, 51, 49, 5, 27, 29, 99, 27, 31, 53, 105, 9, 25, 9, 3, 9, 31, 23]

cp's OEIS Frontend

A247479 Smallest odd k > 1 such that k*2^n+1 is a prime number.

Table of values

List of values

n	a(n)
1	3
2	3
3	5
4	7
5	3
6	3
7	5
8	3
9	15
10	13
11	9
12	3
13	5
14	7
15	5
16	21
17	9
18	3
19	11
20	7
21	11
22	25
23	45
24	45
25	5
26	7
27	15
28	13
29	23
30	3
31	35
32	43
33	9
34	75
35	59
36	3
37	15
38	15
39	5
40	27
41	3
42	9
43	9
44	15
45	35
46	19
47	27
48	15
49	23
50	7
51	17
52	7
53	51
54	49
55	5
56	27
57	29
58	99
59	27
60	31
61	53
62	105
63	9
64	25
65	9
66	3
67	9
68	31
69	23

n	a(n)
1	3
2	3
3	5
4	7
5	3
6	3
7	5
8	3
9	15
10	13
11	9
12	3
13	5
14	7
15	5
16	21
17	9
18	3
19	11
20	7
21	11
22	25
23	45
24	45
25	5
26	7
27	15
28	13
29	23
30	3
31	35
32	43
33	9
34	75
35	59
36	3
37	15
38	15
39	5
40	27
41	3
42	9
43	9
44	15
45	35
46	19
47	27
48	15
49	23
50	7
51	17
52	7
53	51
54	49
55	5
56	27
57	29
58	99
59	27
60	31
61	53
62	105
63	9
64	25
65	9
66	3
67	9
68	31
69	23

n	a(n)
1	3
2	3
3	5
4	7
5	3
6	3
7	5
8	3
9	15
10	13
11	9
12	3
13	5
14	7
15	5
16	21
17	9
18	3
19	11
20	7
21	11
22	25
23	45
24	45
25	5
26	7
27	15
28	13
29	23
30	3
31	35
32	43
33	9
34	75
35	59
36	3
37	15
38	15
39	5
40	27
41	3
42	9
43	9
44	15
45	35
46	19
47	27
48	15
49	23
50	7
51	17
52	7
53	51
54	49
55	5
56	27
57	29
58	99
59	27
60	31
61	53
62	105
63	9
64	25
65	9
66	3
67	9
68	31
69	23