A120642 - cp's OEIS frontend

A120642 Smallest integer k>0 such that k*10^n - 1 is a prime.

n	a(n)
1	2
2	2
3	2
4	5
5	2
6	3
7	2
8	8
9	11
10	6
11	11
12	35
13	6
14	5
15	15
16	14
17	11
18	21
19	3
20	21
21	14
22	6
23	6
24	80
25	8
26	2
27	2
28	6
29	9
30	48
31	48
32	21
33	15
34	6
35	44
36	11
37	9
38	15
39	18
40	6
41	33
42	30
43	3
44	278
45	74
46	92
47	89
48	33
49	8
50	71
51	59
52	11
53	2
54	5
55	3
56	24
57	108
58	47
59	39
60	41
61	6
62	14
63	53
64	173
65	26
66	26
67	51
68	114
69	23
70	17
71	246
72	44
73	6
74	131
75	56
76	8
77	26
78	77
79	74

[2, 2, 2, 5, 2, 3, 2, 8, 11, 6, 11, 35, 6, 5, 15, 14, 11, 21, 3, 21, 14, 6, 6, 80, 8, 2, 2, 6, 9, 48, 48, 21, 15, 6, 44, 11, 9, 15, 18, 6, 33, 30, 3, 278, 74, 92, 89, 33, 8, 71, 59, 11, 2, 5, 3, 24, 108, 47, 39, 41, 6, 14, 53, 173, 26, 26, 51, 114, 23, 17, 246, 44, 6, 131, 56, 8, 26, 77, 74]

cp's OEIS Frontend

A120642 Smallest integer k>0 such that k*10^n - 1 is a prime.

Table of values

List of values

n	a(n)
1	2
2	2
3	2
4	5
5	2
6	3
7	2
8	8
9	11
10	6
11	11
12	35
13	6
14	5
15	15
16	14
17	11
18	21
19	3
20	21
21	14
22	6
23	6
24	80
25	8
26	2
27	2
28	6
29	9
30	48
31	48
32	21
33	15
34	6
35	44
36	11
37	9
38	15
39	18
40	6
41	33
42	30
43	3
44	278
45	74
46	92
47	89
48	33
49	8
50	71
51	59
52	11
53	2
54	5
55	3
56	24
57	108
58	47
59	39
60	41
61	6
62	14
63	53
64	173
65	26
66	26
67	51
68	114
69	23
70	17
71	246
72	44
73	6
74	131
75	56
76	8
77	26
78	77
79	74

n	a(n)
1	2
2	2
3	2
4	5
5	2
6	3
7	2
8	8
9	11
10	6
11	11
12	35
13	6
14	5
15	15
16	14
17	11
18	21
19	3
20	21
21	14
22	6
23	6
24	80
25	8
26	2
27	2
28	6
29	9
30	48
31	48
32	21
33	15
34	6
35	44
36	11
37	9
38	15
39	18
40	6
41	33
42	30
43	3
44	278
45	74
46	92
47	89
48	33
49	8
50	71
51	59
52	11
53	2
54	5
55	3
56	24
57	108
58	47
59	39
60	41
61	6
62	14
63	53
64	173
65	26
66	26
67	51
68	114
69	23
70	17
71	246
72	44
73	6
74	131
75	56
76	8
77	26
78	77
79	74

n	a(n)
1	2
2	2
3	2
4	5
5	2
6	3
7	2
8	8
9	11
10	6
11	11
12	35
13	6
14	5
15	15
16	14
17	11
18	21
19	3
20	21
21	14
22	6
23	6
24	80
25	8
26	2
27	2
28	6
29	9
30	48
31	48
32	21
33	15
34	6
35	44
36	11
37	9
38	15
39	18
40	6
41	33
42	30
43	3
44	278
45	74
46	92
47	89
48	33
49	8
50	71
51	59
52	11
53	2
54	5
55	3
56	24
57	108
58	47
59	39
60	41
61	6
62	14
63	53
64	173
65	26
66	26
67	51
68	114
69	23
70	17
71	246
72	44
73	6
74	131
75	56
76	8
77	26
78	77
79	74