A255598 - cp's OEIS frontend

A255598 a(n) is the minimal number q>1 such that n(q+1)-1 is prime, or -1 if no such q exists.

n	a(n)
1	2
2	2
3	3
4	2
5	3
6	2
7	5
8	2
9	5
10	2
11	3
12	3
13	7
14	2
15	3
16	2
17	3
18	2
19	5
20	2
21	3
22	4
23	5
24	2
25	5
26	3
27	3
28	2
29	5
30	2
31	13
32	3
33	3
34	2
35	3
36	2
37	11
38	2
39	5
40	4
41	3
42	3
43	5
44	2
45	3
46	2
47	5
48	3
49	5
50	2
51	9
52	5
53	3
54	4
55	7
56	2
57	3
58	2
59	5
60	2
61	7
62	6
63	3
64	2
65	5
66	2
67	5
68	3
69	11
70	4
71	3
72	4
73	13
74	5
75	5
76	2
77	3
78	2
79	7
80	2
81	7
82	4
83	3
84	2
85	5
86	2
87	3
88	2
89	15
90	2
91	7
92	3
93	5
94	2
95	3
96	3
97	11

[2, 2, 3, 2, 3, 2, 5, 2, 5, 2, 3, 3, 7, 2, 3, 2, 3, 2, 5, 2, 3, 4, 5, 2, 5, 3, 3, 2, 5, 2, 13, 3, 3, 2, 3, 2, 11, 2, 5, 4, 3, 3, 5, 2, 3, 2, 5, 3, 5, 2, 9, 5, 3, 4, 7, 2, 3, 2, 5, 2, 7, 6, 3, 2, 5, 2, 5, 3, 11, 4, 3, 4, 13, 5, 5, 2, 3, 2, 7, 2, 7, 4, 3, 2, 5, 2, 3, 2, 15, 2, 7, 3, 5, 2, 3, 3, 11]

cp's OEIS Frontend

A255598 a(n) is the minimal number q>1 such that n(q+1)-1 is prime, or -1 if no such q exists.

Table of values

List of values

n	a(n)
1	2
2	2
3	3
4	2
5	3
6	2
7	5
8	2
9	5
10	2
11	3
12	3
13	7
14	2
15	3
16	2
17	3
18	2
19	5
20	2
21	3
22	4
23	5
24	2
25	5
26	3
27	3
28	2
29	5
30	2
31	13
32	3
33	3
34	2
35	3
36	2
37	11
38	2
39	5
40	4
41	3
42	3
43	5
44	2
45	3
46	2
47	5
48	3
49	5
50	2
51	9
52	5
53	3
54	4
55	7
56	2
57	3
58	2
59	5
60	2
61	7
62	6
63	3
64	2
65	5
66	2
67	5
68	3
69	11
70	4
71	3
72	4
73	13
74	5
75	5
76	2
77	3
78	2
79	7
80	2
81	7
82	4
83	3
84	2
85	5
86	2
87	3
88	2
89	15
90	2
91	7
92	3
93	5
94	2
95	3
96	3
97	11

n	a(n)
1	2
2	2
3	3
4	2
5	3
6	2
7	5
8	2
9	5
10	2
11	3
12	3
13	7
14	2
15	3
16	2
17	3
18	2
19	5
20	2
21	3
22	4
23	5
24	2
25	5
26	3
27	3
28	2
29	5
30	2
31	13
32	3
33	3
34	2
35	3
36	2
37	11
38	2
39	5
40	4
41	3
42	3
43	5
44	2
45	3
46	2
47	5
48	3
49	5
50	2
51	9
52	5
53	3
54	4
55	7
56	2
57	3
58	2
59	5
60	2
61	7
62	6
63	3
64	2
65	5
66	2
67	5
68	3
69	11
70	4
71	3
72	4
73	13
74	5
75	5
76	2
77	3
78	2
79	7
80	2
81	7
82	4
83	3
84	2
85	5
86	2
87	3
88	2
89	15
90	2
91	7
92	3
93	5
94	2
95	3
96	3
97	11

n	a(n)
1	2
2	2
3	3
4	2
5	3
6	2
7	5
8	2
9	5
10	2
11	3
12	3
13	7
14	2
15	3
16	2
17	3
18	2
19	5
20	2
21	3
22	4
23	5
24	2
25	5
26	3
27	3
28	2
29	5
30	2
31	13
32	3
33	3
34	2
35	3
36	2
37	11
38	2
39	5
40	4
41	3
42	3
43	5
44	2
45	3
46	2
47	5
48	3
49	5
50	2
51	9
52	5
53	3
54	4
55	7
56	2
57	3
58	2
59	5
60	2
61	7
62	6
63	3
64	2
65	5
66	2
67	5
68	3
69	11
70	4
71	3
72	4
73	13
74	5
75	5
76	2
77	3
78	2
79	7
80	2
81	7
82	4
83	3
84	2
85	5
86	2
87	3
88	2
89	15
90	2
91	7
92	3
93	5
94	2
95	3
96	3
97	11