A087605 - cp's OEIS frontend

A087605 Smallest k such that n times concatenation of k with itself followed by a 7 is a prime, or 0 if no such number exists.

n	a(n)
1	1
2	2
3	1
4	1
5	3
6	100005
7	1
8	2
9	4
10	6
11	8
12	100010
13	19
14	2
15	215
16	9
17	60
18	100041
19	4
20	66
21	5
22	1
23	41
24	100061
25	4
26	15
27	2
28	1
29	195
30	100055
31	61
32	1061
33	143
34	12
35	72
36	100127
37	19
38	60
39	1
40	6
41	125
42	0
43	45
44	1305
45	3
46	39
47	27
48	100269
49	72
50	95
51	136
52	1123
53	50
54	100193
55	52
56	1056
57	176
58	1536
59	66

[1, 2, 1, 1, 3, 100005, 1, 2, 4, 6, 8, 100010, 19, 2, 215, 9, 60, 100041, 4, 66, 5, 1, 41, 100061, 4, 15, 2, 1, 195, 100055, 61, 1061, 143, 12, 72, 100127, 19, 60, 1, 6, 125, 0, 45, 1305, 3, 39, 27, 100269, 72, 95, 136, 1123, 50, 100193, 52, 1056, 176, 1536, 66]

cp's OEIS Frontend

A087605 Smallest k such that n times concatenation of k with itself followed by a 7 is a prime, or 0 if no such number exists.

Table of values

List of values