A280314 - cp's OEIS frontend

A280314 Relationship of prime numbers to multiples of 6. The value of a(n) = 2 if n6 has two neighboring primes, a(n) = 1 if only n6+1 is prime, a(n) = -1 if only n6-1 is prime, and a(n) = 0 if the neighbors of n6 are both composite.

n	a(n)
1	2
2	2
3	2
4	-1
5	2
6	1
7	2
8	-1
9	-1
10	2
11	1
12	2
13	1
14	-1
15	-1
16	1
17	2
18	2
19	-1
20	0
21	1
22	-1
23	2
24	0
25	2
26	1
27	1
28	-1
29	-1
30	2
31	0
32	2
33	2
34	0
35	1
36	0
37	1
38	2
39	-1
40	2
41	0
42	-1
43	-1
44	-1
45	2
46	1
47	2
48	0
49	-1
50	0
51	1
52	2
53	-1
54	0
55	1
56	1
57	0
58	2
59	-1
60	-1
61	1
62	1
63	1
64	-1
65	-1
66	1
67	-1
68	1
69	0
70	2
71	0
72	2
73	1
74	-1
75	-1
76	1
77	2
78	-1
79	0
80	-1
81	1
82	-1
83	1
84	-1
85	-1
86	0
87	2
88	0
89	0
90	1
91	1

[2, 2, 2, -1, 2, 1, 2, -1, -1, 2, 1, 2, 1, -1, -1, 1, 2, 2, -1, 0, 1, -1, 2, 0, 2, 1, 1, -1, -1, 2, 0, 2, 2, 0, 1, 0, 1, 2, -1, 2, 0, -1, -1, -1, 2, 1, 2, 0, -1, 0, 1, 2, -1, 0, 1, 1, 0, 2, -1, -1, 1, 1, 1, -1, -1, 1, -1, 1, 0, 2, 0, 2, 1, -1, -1, 1, 2, -1, 0, -1, 1, -1, 1, -1, -1, 0, 2, 0, 0, 1, 1]

cp's OEIS Frontend

A280314 Relationship of prime numbers to multiples of 6. The value of a(n) = 2 if n6 has two neighboring primes, a(n) = 1 if only n6+1 is prime, a(n) = -1 if only n6-1 is prime, and a(n) = 0 if the neighbors of n6 are both composite.

Table of values

List of values

n	a(n)
1	2
2	2
3	2
4	-1
5	2
6	1
7	2
8	-1
9	-1
10	2
11	1
12	2
13	1
14	-1
15	-1
16	1
17	2
18	2
19	-1
20	0
21	1
22	-1
23	2
24	0
25	2
26	1
27	1
28	-1
29	-1
30	2
31	0
32	2
33	2
34	0
35	1
36	0
37	1
38	2
39	-1
40	2
41	0
42	-1
43	-1
44	-1
45	2
46	1
47	2
48	0
49	-1
50	0
51	1
52	2
53	-1
54	0
55	1
56	1
57	0
58	2
59	-1
60	-1
61	1
62	1
63	1
64	-1
65	-1
66	1
67	-1
68	1
69	0
70	2
71	0
72	2
73	1
74	-1
75	-1
76	1
77	2
78	-1
79	0
80	-1
81	1
82	-1
83	1
84	-1
85	-1
86	0
87	2
88	0
89	0
90	1
91	1

n	a(n)
1	2
2	2
3	2
4	-1
5	2
6	1
7	2
8	-1
9	-1
10	2
11	1
12	2
13	1
14	-1
15	-1
16	1
17	2
18	2
19	-1
20	0
21	1
22	-1
23	2
24	0
25	2
26	1
27	1
28	-1
29	-1
30	2
31	0
32	2
33	2
34	0
35	1
36	0
37	1
38	2
39	-1
40	2
41	0
42	-1
43	-1
44	-1
45	2
46	1
47	2
48	0
49	-1
50	0
51	1
52	2
53	-1
54	0
55	1
56	1
57	0
58	2
59	-1
60	-1
61	1
62	1
63	1
64	-1
65	-1
66	1
67	-1
68	1
69	0
70	2
71	0
72	2
73	1
74	-1
75	-1
76	1
77	2
78	-1
79	0
80	-1
81	1
82	-1
83	1
84	-1
85	-1
86	0
87	2
88	0
89	0
90	1
91	1

cp's OEIS Frontend

A280314 Relationship of prime numbers to multiples of 6. The value of a(n) = 2 if n*6 has two neighboring primes, a(n) = 1 if only n*6+1 is prime, a(n) = -1 if only n*6-1 is prime, and a(n) = 0 if the neighbors of n*6 are both composite.

Table of values

List of values

A280314 Relationship of prime numbers to multiples of 6. The value of a(n) = 2 if n6 has two neighboring primes, a(n) = 1 if only n6+1 is prime, a(n) = -1 if only n6-1 is prime, and a(n) = 0 if the neighbors of n6 are both composite.

n	a(n)
1	2
2	2
3	2
4	-1
5	2
6	1
7	2
8	-1
9	-1
10	2
11	1
12	2
13	1
14	-1
15	-1
16	1
17	2
18	2
19	-1
20	0
21	1
22	-1
23	2
24	0
25	2
26	1
27	1
28	-1
29	-1
30	2
31	0
32	2
33	2
34	0
35	1
36	0
37	1
38	2
39	-1
40	2
41	0
42	-1
43	-1
44	-1
45	2
46	1
47	2
48	0
49	-1
50	0
51	1
52	2
53	-1
54	0
55	1
56	1
57	0
58	2
59	-1
60	-1
61	1
62	1
63	1
64	-1
65	-1
66	1
67	-1
68	1
69	0
70	2
71	0
72	2
73	1
74	-1
75	-1
76	1
77	2
78	-1
79	0
80	-1
81	1
82	-1
83	1
84	-1
85	-1
86	0
87	2
88	0
89	0
90	1
91	1