A360097 - cp's OEIS frontend

A360097 a(n) = smallest k such that 2nk-1 and 2nk+1 are nonprimes.

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

[13, 14, 20, 7, 5, 10, 4, 4, 8, 6, 7, 5, 1, 2, 4, 2, 1, 4, 2, 3, 17, 4, 2, 3, 1, 4, 4, 1, 2, 2, 2, 1, 8, 3, 8, 2, 4, 1, 8, 2, 3, 11, 1, 2, 10, 1, 1, 3, 4, 3, 2, 2, 4, 2, 2, 5, 3, 1, 1, 1, 1, 1, 9, 4, 2, 4, 1, 4, 3, 4, 1, 1, 1, 2, 2, 2, 1, 4, 3, 1, 2, 2, 4, 7, 1]

cp's OEIS Frontend

A360097 a(n) = smallest k such that 2nk-1 and 2nk+1 are nonprimes.

Table of values

List of values

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

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

cp's OEIS Frontend

A360097 a(n) = smallest k such that 2*n*k-1 and 2*n*k+1 are nonprimes.

Table of values

List of values

A360097 a(n) = smallest k such that 2nk-1 and 2nk+1 are nonprimes.

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