A175210 - cp's OEIS frontend

A175210 a(n) = largest prime (or 1, if no such prime exists) that is < p(n) and whose binary representation occurs as a substring in the binary representation of p(n), where p(n) is the n-th prime.

n	a(n)
1	1
2	1
3	2
4	3
5	5
6	5
7	2
8	3
9	11
10	13
11	7
12	5
13	5
14	11
15	23
16	13
17	29
18	29
19	3
20	17
21	2
22	19
23	41
24	11
25	3
26	37
27	19
28	53
29	13
30	17
31	31
32	3
33	17
34	17
35	37
36	37
37	29
38	17
39	83
40	43
41	89
42	53
43	47
44	3
45	17
46	71
47	83
48	47
49	113
50	101
51	41
52	59
53	113
54	61
55	2
56	131
57	67
58	67
59	17
60	17
61	17
62	73
63	19
64	23
65	19
66	79
67	41
68	17
69	173
70	43
71	97
72	179
73	47

[1, 1, 2, 3, 5, 5, 2, 3, 11, 13, 7, 5, 5, 11, 23, 13, 29, 29, 3, 17, 2, 19, 41, 11, 3, 37, 19, 53, 13, 17, 31, 3, 17, 17, 37, 37, 29, 17, 83, 43, 89, 53, 47, 3, 17, 71, 83, 47, 113, 101, 41, 59, 113, 61, 2, 131, 67, 67, 17, 17, 17, 73, 19, 23, 19, 79, 41, 17, 173, 43, 97, 179, 47]

cp's OEIS Frontend

A175210 a(n) = largest prime (or 1, if no such prime exists) that is < p(n) and whose binary representation occurs as a substring in the binary representation of p(n), where p(n) is the n-th prime.

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	3
5	5
6	5
7	2
8	3
9	11
10	13
11	7
12	5
13	5
14	11
15	23
16	13
17	29
18	29
19	3
20	17
21	2
22	19
23	41
24	11
25	3
26	37
27	19
28	53
29	13
30	17
31	31
32	3
33	17
34	17
35	37
36	37
37	29
38	17
39	83
40	43
41	89
42	53
43	47
44	3
45	17
46	71
47	83
48	47
49	113
50	101
51	41
52	59
53	113
54	61
55	2
56	131
57	67
58	67
59	17
60	17
61	17
62	73
63	19
64	23
65	19
66	79
67	41
68	17
69	173
70	43
71	97
72	179
73	47

n	a(n)
1	1
2	1
3	2
4	3
5	5
6	5
7	2
8	3
9	11
10	13
11	7
12	5
13	5
14	11
15	23
16	13
17	29
18	29
19	3
20	17
21	2
22	19
23	41
24	11
25	3
26	37
27	19
28	53
29	13
30	17
31	31
32	3
33	17
34	17
35	37
36	37
37	29
38	17
39	83
40	43
41	89
42	53
43	47
44	3
45	17
46	71
47	83
48	47
49	113
50	101
51	41
52	59
53	113
54	61
55	2
56	131
57	67
58	67
59	17
60	17
61	17
62	73
63	19
64	23
65	19
66	79
67	41
68	17
69	173
70	43
71	97
72	179
73	47

n	a(n)
1	1
2	1
3	2
4	3
5	5
6	5
7	2
8	3
9	11
10	13
11	7
12	5
13	5
14	11
15	23
16	13
17	29
18	29
19	3
20	17
21	2
22	19
23	41
24	11
25	3
26	37
27	19
28	53
29	13
30	17
31	31
32	3
33	17
34	17
35	37
36	37
37	29
38	17
39	83
40	43
41	89
42	53
43	47
44	3
45	17
46	71
47	83
48	47
49	113
50	101
51	41
52	59
53	113
54	61
55	2
56	131
57	67
58	67
59	17
60	17
61	17
62	73
63	19
64	23
65	19
66	79
67	41
68	17
69	173
70	43
71	97
72	179
73	47