A036012 - cp's OEIS frontend

A036012 a(n) = smallest number > 1 such that a(1)a(2)...a(n) + 1 is prime.

n	a(n)
1	2
2	2
3	3
4	3
5	2
6	6
7	3
8	2
9	4
10	7
11	7
12	3
13	8
14	6
15	2
16	3
17	6
18	9
19	6
20	14
21	19
22	11
23	4
24	4
25	19
26	4
27	13
28	3
29	10
30	13
31	15
32	4
33	11
34	9
35	2
36	5
37	26
38	19
39	52
40	21
41	20
42	63
43	4
44	19
45	17
46	6
47	29
48	19
49	3
50	5
51	51
52	11
53	14
54	15
55	7
56	12
57	44
58	34
59	7
60	21
61	32
62	3
63	22
64	10
65	19
66	19
67	7
68	20
69	4
70	22
71	4
72	17
73	35
74	47
75	40
76	14
77	5
78	14
79	36
80	39
81	16

[2, 2, 3, 3, 2, 6, 3, 2, 4, 7, 7, 3, 8, 6, 2, 3, 6, 9, 6, 14, 19, 11, 4, 4, 19, 4, 13, 3, 10, 13, 15, 4, 11, 9, 2, 5, 26, 19, 52, 21, 20, 63, 4, 19, 17, 6, 29, 19, 3, 5, 51, 11, 14, 15, 7, 12, 44, 34, 7, 21, 32, 3, 22, 10, 19, 19, 7, 20, 4, 22, 4, 17, 35, 47, 40, 14, 5, 14, 36, 39, 16]

cp's OEIS Frontend

A036012 a(n) = smallest number > 1 such that a(1)a(2)...a(n) + 1 is prime.

Table of values

List of values

n	a(n)
1	2
2	2
3	3
4	3
5	2
6	6
7	3
8	2
9	4
10	7
11	7
12	3
13	8
14	6
15	2
16	3
17	6
18	9
19	6
20	14
21	19
22	11
23	4
24	4
25	19
26	4
27	13
28	3
29	10
30	13
31	15
32	4
33	11
34	9
35	2
36	5
37	26
38	19
39	52
40	21
41	20
42	63
43	4
44	19
45	17
46	6
47	29
48	19
49	3
50	5
51	51
52	11
53	14
54	15
55	7
56	12
57	44
58	34
59	7
60	21
61	32
62	3
63	22
64	10
65	19
66	19
67	7
68	20
69	4
70	22
71	4
72	17
73	35
74	47
75	40
76	14
77	5
78	14
79	36
80	39
81	16

n	a(n)
1	2
2	2
3	3
4	3
5	2
6	6
7	3
8	2
9	4
10	7
11	7
12	3
13	8
14	6
15	2
16	3
17	6
18	9
19	6
20	14
21	19
22	11
23	4
24	4
25	19
26	4
27	13
28	3
29	10
30	13
31	15
32	4
33	11
34	9
35	2
36	5
37	26
38	19
39	52
40	21
41	20
42	63
43	4
44	19
45	17
46	6
47	29
48	19
49	3
50	5
51	51
52	11
53	14
54	15
55	7
56	12
57	44
58	34
59	7
60	21
61	32
62	3
63	22
64	10
65	19
66	19
67	7
68	20
69	4
70	22
71	4
72	17
73	35
74	47
75	40
76	14
77	5
78	14
79	36
80	39
81	16

n	a(n)
1	2
2	2
3	3
4	3
5	2
6	6
7	3
8	2
9	4
10	7
11	7
12	3
13	8
14	6
15	2
16	3
17	6
18	9
19	6
20	14
21	19
22	11
23	4
24	4
25	19
26	4
27	13
28	3
29	10
30	13
31	15
32	4
33	11
34	9
35	2
36	5
37	26
38	19
39	52
40	21
41	20
42	63
43	4
44	19
45	17
46	6
47	29
48	19
49	3
50	5
51	51
52	11
53	14
54	15
55	7
56	12
57	44
58	34
59	7
60	21
61	32
62	3
63	22
64	10
65	19
66	19
67	7
68	20
69	4
70	22
71	4
72	17
73	35
74	47
75	40
76	14
77	5
78	14
79	36
80	39
81	16