A174287 - cp's OEIS frontend

A174287 Smallest natural square base q = q(k) that concatenation prime(k)//prime(k+1)//q^2 (k = 1, 2, ...) is a prime number.

n	a(n)
1	3
2	3
3	1
4	11
5	1
6	1
7	1
8	1
9	1
10	1
11	3
12	7
13	31
14	13
15	9
16	1
17	1
18	141
19	53
20	37
21	9
22	11
23	1
24	7
25	61
26	7
27	17
28	13
29	17
30	1
31	17
32	11
33	7
34	23
35	7
36	27
37	27
38	7
39	1
40	9
41	19
42	29
43	7
44	29
45	19
46	3
47	3
48	1
49	43
50	67
51	1
52	7
53	7
54	9
55	9
56	1
57	13
58	21
59	7
60	7
61	7
62	1
63	1
64	43
65	1
66	1
67	57
68	1
69	67
70	7
71	17

[3, 3, 1, 11, 1, 1, 1, 1, 1, 1, 3, 7, 31, 13, 9, 1, 1, 141, 53, 37, 9, 11, 1, 7, 61, 7, 17, 13, 17, 1, 17, 11, 7, 23, 7, 27, 27, 7, 1, 9, 19, 29, 7, 29, 19, 3, 3, 1, 43, 67, 1, 7, 7, 9, 9, 1, 13, 21, 7, 7, 7, 1, 1, 43, 1, 1, 57, 1, 67, 7, 17]

cp's OEIS Frontend

A174287 Smallest natural square base q = q(k) that concatenation prime(k)//prime(k+1)//q^2 (k = 1, 2, ...) is a prime number.

Table of values

List of values

n	a(n)
1	3
2	3
3	1
4	11
5	1
6	1
7	1
8	1
9	1
10	1
11	3
12	7
13	31
14	13
15	9
16	1
17	1
18	141
19	53
20	37
21	9
22	11
23	1
24	7
25	61
26	7
27	17
28	13
29	17
30	1
31	17
32	11
33	7
34	23
35	7
36	27
37	27
38	7
39	1
40	9
41	19
42	29
43	7
44	29
45	19
46	3
47	3
48	1
49	43
50	67
51	1
52	7
53	7
54	9
55	9
56	1
57	13
58	21
59	7
60	7
61	7
62	1
63	1
64	43
65	1
66	1
67	57
68	1
69	67
70	7
71	17

n	a(n)
1	3
2	3
3	1
4	11
5	1
6	1
7	1
8	1
9	1
10	1
11	3
12	7
13	31
14	13
15	9
16	1
17	1
18	141
19	53
20	37
21	9
22	11
23	1
24	7
25	61
26	7
27	17
28	13
29	17
30	1
31	17
32	11
33	7
34	23
35	7
36	27
37	27
38	7
39	1
40	9
41	19
42	29
43	7
44	29
45	19
46	3
47	3
48	1
49	43
50	67
51	1
52	7
53	7
54	9
55	9
56	1
57	13
58	21
59	7
60	7
61	7
62	1
63	1
64	43
65	1
66	1
67	57
68	1
69	67
70	7
71	17

n	a(n)
1	3
2	3
3	1
4	11
5	1
6	1
7	1
8	1
9	1
10	1
11	3
12	7
13	31
14	13
15	9
16	1
17	1
18	141
19	53
20	37
21	9
22	11
23	1
24	7
25	61
26	7
27	17
28	13
29	17
30	1
31	17
32	11
33	7
34	23
35	7
36	27
37	27
38	7
39	1
40	9
41	19
42	29
43	7
44	29
45	19
46	3
47	3
48	1
49	43
50	67
51	1
52	7
53	7
54	9
55	9
56	1
57	13
58	21
59	7
60	7
61	7
62	1
63	1
64	43
65	1
66	1
67	57
68	1
69	67
70	7
71	17