A076689 - cp's OEIS frontend

A076689 Smallest k such that k*prime(n)# + 1 is prime where prime(n)# is the n-th primorial number A002110(n).

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	4
7	8
8	11
9	4
10	11
11	1
12	4
13	7
14	6
15	14
16	3
17	5
18	2
19	7
20	3
21	6
22	20
23	2
24	9
25	20
26	2
27	5
28	7
29	31
30	2
31	12
32	13
33	24
34	7
35	39
36	21
37	35
38	24
39	22
40	3
41	21
42	8
43	9
44	13
45	39
46	21
47	29
48	10
49	3
50	62
51	52
52	21
53	3
54	36
55	28
56	15
57	18
58	33
59	7
60	46
61	33
62	20
63	14
64	22
65	41
66	7
67	27
68	39
69	20
70	4
71	4
72	5
73	15
74	27
75	1
76	44
77	99
78	9
79	52
80	2
81	27
82	12

[1, 1, 1, 1, 1, 4, 8, 11, 4, 11, 1, 4, 7, 6, 14, 3, 5, 2, 7, 3, 6, 20, 2, 9, 20, 2, 5, 7, 31, 2, 12, 13, 24, 7, 39, 21, 35, 24, 22, 3, 21, 8, 9, 13, 39, 21, 29, 10, 3, 62, 52, 21, 3, 36, 28, 15, 18, 33, 7, 46, 33, 20, 14, 22, 41, 7, 27, 39, 20, 4, 4, 5, 15, 27, 1, 44, 99, 9, 52, 2, 27, 12]

cp's OEIS Frontend

A076689 Smallest k such that k*prime(n)# + 1 is prime where prime(n)# is the n-th primorial number A002110(n).

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	4
7	8
8	11
9	4
10	11
11	1
12	4
13	7
14	6
15	14
16	3
17	5
18	2
19	7
20	3
21	6
22	20
23	2
24	9
25	20
26	2
27	5
28	7
29	31
30	2
31	12
32	13
33	24
34	7
35	39
36	21
37	35
38	24
39	22
40	3
41	21
42	8
43	9
44	13
45	39
46	21
47	29
48	10
49	3
50	62
51	52
52	21
53	3
54	36
55	28
56	15
57	18
58	33
59	7
60	46
61	33
62	20
63	14
64	22
65	41
66	7
67	27
68	39
69	20
70	4
71	4
72	5
73	15
74	27
75	1
76	44
77	99
78	9
79	52
80	2
81	27
82	12

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	4
7	8
8	11
9	4
10	11
11	1
12	4
13	7
14	6
15	14
16	3
17	5
18	2
19	7
20	3
21	6
22	20
23	2
24	9
25	20
26	2
27	5
28	7
29	31
30	2
31	12
32	13
33	24
34	7
35	39
36	21
37	35
38	24
39	22
40	3
41	21
42	8
43	9
44	13
45	39
46	21
47	29
48	10
49	3
50	62
51	52
52	21
53	3
54	36
55	28
56	15
57	18
58	33
59	7
60	46
61	33
62	20
63	14
64	22
65	41
66	7
67	27
68	39
69	20
70	4
71	4
72	5
73	15
74	27
75	1
76	44
77	99
78	9
79	52
80	2
81	27
82	12

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	4
7	8
8	11
9	4
10	11
11	1
12	4
13	7
14	6
15	14
16	3
17	5
18	2
19	7
20	3
21	6
22	20
23	2
24	9
25	20
26	2
27	5
28	7
29	31
30	2
31	12
32	13
33	24
34	7
35	39
36	21
37	35
38	24
39	22
40	3
41	21
42	8
43	9
44	13
45	39
46	21
47	29
48	10
49	3
50	62
51	52
52	21
53	3
54	36
55	28
56	15
57	18
58	33
59	7
60	46
61	33
62	20
63	14
64	22
65	41
66	7
67	27
68	39
69	20
70	4
71	4
72	5
73	15
74	27
75	1
76	44
77	99
78	9
79	52
80	2
81	27
82	12