A103689 - cp's OEIS frontend

A103689 a(n) is the least k such that either kn - 1 or kn + 1 (or both) is prime.

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	2
12	1
13	4
14	1
15	2
16	1
17	4
18	1
19	2
20	1
21	2
22	1
23	2
24	1
25	4
26	2
27	2
28	1
29	2
30	1
31	2
32	1
33	2
34	2
35	2
36	1
37	2
38	1
39	2
40	1
41	2
42	1
43	4
44	1
45	2
46	1
47	6
48	1
49	2
50	2
51	2
52	1
53	2
54	1
55	2
56	2
57	2
58	1
59	6
60	1
61	6
62	1
63	2
64	2
65	2
66	1
67	4
68	1
69	2
70	1
71	4
72	1
73	4
74	1
75	2
76	2
77	4
78	1
79	2
80	1
81	2
82	1
83	2
84	1
85	6
86	2
87	2
88	1
89	2
90	1
91	2
92	3
93	4
94	3
95	2
96	1
97	2
98	1
99	2
100	1
101	6
102	1
103	6
104	1
105	2

[1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 2, 1, 2, 1, 4, 2, 2, 1, 2, 1, 2, 1, 2, 2, 2, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 6, 1, 2, 2, 2, 1, 2, 1, 2, 2, 2, 1, 6, 1, 6, 1, 2, 2, 2, 1, 4, 1, 2, 1, 4, 1, 4, 1, 2, 2, 4, 1, 2, 1, 2, 1, 2, 1, 6, 2, 2, 1, 2, 1, 2, 3, 4, 3, 2, 1, 2, 1, 2, 1, 6, 1, 6, 1, 2]

cp's OEIS Frontend

A103689 a(n) is the least k such that either kn - 1 or kn + 1 (or both) is prime.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	2
12	1
13	4
14	1
15	2
16	1
17	4
18	1
19	2
20	1
21	2
22	1
23	2
24	1
25	4
26	2
27	2
28	1
29	2
30	1
31	2
32	1
33	2
34	2
35	2
36	1
37	2
38	1
39	2
40	1
41	2
42	1
43	4
44	1
45	2
46	1
47	6
48	1
49	2
50	2
51	2
52	1
53	2
54	1
55	2
56	2
57	2
58	1
59	6
60	1
61	6
62	1
63	2
64	2
65	2
66	1
67	4
68	1
69	2
70	1
71	4
72	1
73	4
74	1
75	2
76	2
77	4
78	1
79	2
80	1
81	2
82	1
83	2
84	1
85	6
86	2
87	2
88	1
89	2
90	1
91	2
92	3
93	4
94	3
95	2
96	1
97	2
98	1
99	2
100	1
101	6
102	1
103	6
104	1
105	2

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	2
12	1
13	4
14	1
15	2
16	1
17	4
18	1
19	2
20	1
21	2
22	1
23	2
24	1
25	4
26	2
27	2
28	1
29	2
30	1
31	2
32	1
33	2
34	2
35	2
36	1
37	2
38	1
39	2
40	1
41	2
42	1
43	4
44	1
45	2
46	1
47	6
48	1
49	2
50	2
51	2
52	1
53	2
54	1
55	2
56	2
57	2
58	1
59	6
60	1
61	6
62	1
63	2
64	2
65	2
66	1
67	4
68	1
69	2
70	1
71	4
72	1
73	4
74	1
75	2
76	2
77	4
78	1
79	2
80	1
81	2
82	1
83	2
84	1
85	6
86	2
87	2
88	1
89	2
90	1
91	2
92	3
93	4
94	3
95	2
96	1
97	2
98	1
99	2
100	1
101	6
102	1
103	6
104	1
105	2

cp's OEIS Frontend

A103689 a(n) is the least k such that either k*n - 1 or k*n + 1 (or both) is prime.

Table of values

List of values

A103689 a(n) is the least k such that either kn - 1 or kn + 1 (or both) is prime.

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	2
12	1
13	4
14	1
15	2
16	1
17	4
18	1
19	2
20	1
21	2
22	1
23	2
24	1
25	4
26	2
27	2
28	1
29	2
30	1
31	2
32	1
33	2
34	2
35	2
36	1
37	2
38	1
39	2
40	1
41	2
42	1
43	4
44	1
45	2
46	1
47	6
48	1
49	2
50	2
51	2
52	1
53	2
54	1
55	2
56	2
57	2
58	1
59	6
60	1
61	6
62	1
63	2
64	2
65	2
66	1
67	4
68	1
69	2
70	1
71	4
72	1
73	4
74	1
75	2
76	2
77	4
78	1
79	2
80	1
81	2
82	1
83	2
84	1
85	6
86	2
87	2
88	1
89	2
90	1
91	2
92	3
93	4
94	3
95	2
96	1
97	2
98	1
99	2
100	1
101	6
102	1
103	6
104	1
105	2