A176379 - cp's OEIS frontend

A176379 The smallest prime q which stays prime through at least two iterations of q -> := 2 * q + prime(n+1).

n	a(n)
1	2
2	7
3	2
4	31
5	2
6	7
7	11
8	7
9	19
10	5
11	5
12	19
13	2
14	13
15	13
16	61
17	11
18	17
19	61
20	5
21	5
22	7
23	139
24	5
25	19
26	2
27	103
28	29
29	7
30	2
31	109
32	7
33	59
34	31
35	41
36	5
37	5
38	127
39	13
40	31
41	5
42	109
43	2
44	7
45	41
46	11
47	2
48	7
49	101
50	67
51	79
52	5
53	31
54	13
55	37
56	19
57	11
58	2
59	109
60	53
61	7
62	2
63	19
64	2
65	127
66	29
67	5
68	13
69	59
70	7
71	19
72	47
73	47
74	11
75	13
76	79
77	17
78	19
79	89
80	619

[2, 7, 2, 31, 2, 7, 11, 7, 19, 5, 5, 19, 2, 13, 13, 61, 11, 17, 61, 5, 5, 7, 139, 5, 19, 2, 103, 29, 7, 2, 109, 7, 59, 31, 41, 5, 5, 127, 13, 31, 5, 109, 2, 7, 41, 11, 2, 7, 101, 67, 79, 5, 31, 13, 37, 19, 11, 2, 109, 53, 7, 2, 19, 2, 127, 29, 5, 13, 59, 7, 19, 47, 47, 11, 13, 79, 17, 19, 89, 619]

cp's OEIS Frontend

A176379 The smallest prime q which stays prime through at least two iterations of q -> := 2 * q + prime(n+1).

Table of values

List of values

n	a(n)
1	2
2	7
3	2
4	31
5	2
6	7
7	11
8	7
9	19
10	5
11	5
12	19
13	2
14	13
15	13
16	61
17	11
18	17
19	61
20	5
21	5
22	7
23	139
24	5
25	19
26	2
27	103
28	29
29	7
30	2
31	109
32	7
33	59
34	31
35	41
36	5
37	5
38	127
39	13
40	31
41	5
42	109
43	2
44	7
45	41
46	11
47	2
48	7
49	101
50	67
51	79
52	5
53	31
54	13
55	37
56	19
57	11
58	2
59	109
60	53
61	7
62	2
63	19
64	2
65	127
66	29
67	5
68	13
69	59
70	7
71	19
72	47
73	47
74	11
75	13
76	79
77	17
78	19
79	89
80	619

n	a(n)
1	2
2	7
3	2
4	31
5	2
6	7
7	11
8	7
9	19
10	5
11	5
12	19
13	2
14	13
15	13
16	61
17	11
18	17
19	61
20	5
21	5
22	7
23	139
24	5
25	19
26	2
27	103
28	29
29	7
30	2
31	109
32	7
33	59
34	31
35	41
36	5
37	5
38	127
39	13
40	31
41	5
42	109
43	2
44	7
45	41
46	11
47	2
48	7
49	101
50	67
51	79
52	5
53	31
54	13
55	37
56	19
57	11
58	2
59	109
60	53
61	7
62	2
63	19
64	2
65	127
66	29
67	5
68	13
69	59
70	7
71	19
72	47
73	47
74	11
75	13
76	79
77	17
78	19
79	89
80	619

n	a(n)
1	2
2	7
3	2
4	31
5	2
6	7
7	11
8	7
9	19
10	5
11	5
12	19
13	2
14	13
15	13
16	61
17	11
18	17
19	61
20	5
21	5
22	7
23	139
24	5
25	19
26	2
27	103
28	29
29	7
30	2
31	109
32	7
33	59
34	31
35	41
36	5
37	5
38	127
39	13
40	31
41	5
42	109
43	2
44	7
45	41
46	11
47	2
48	7
49	101
50	67
51	79
52	5
53	31
54	13
55	37
56	19
57	11
58	2
59	109
60	53
61	7
62	2
63	19
64	2
65	127
66	29
67	5
68	13
69	59
70	7
71	19
72	47
73	47
74	11
75	13
76	79
77	17
78	19
79	89
80	619