A220431 - cp's OEIS frontend

A220431 Number of ways to write n=x+y (x>0, y>0) with 3x-1, 3x+1 and xy-1 all prime.

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	2
7	2
8	2
9	3
10	2
11	2
12	3
13	2
14	2
15	3
16	3
17	2
18	3
19	2
20	2
21	6
22	1
23	3
24	6
25	4
26	3
27	3
28	2
29	3
30	4
31	3
32	4
33	2
34	3
35	3
36	5
37	4
38	4
39	7
40	1
41	2
42	5
43	1
44	5
45	7
46	4
47	2
48	3
49	7
50	4
51	7
52	2
53	4
54	7
55	4
56	4
57	5
58	2
59	5
60	8
61	4
62	3
63	3
64	5
65	2
66	8
67	5
68	4
69	3
70	10
71	7
72	8
73	2
74	3
75	5
76	5
77	3
78	6
79	3
80	3
81	14
82	4
83	3
84	12
85	3
86	7
87	7
88	5
89	6
90	8
91	7
92	5
93	9
94	9
95	4
96	4
97	3
98	6
99	10
100	8

[0, 0, 0, 1, 2, 2, 2, 2, 3, 2, 2, 3, 2, 2, 3, 3, 2, 3, 2, 2, 6, 1, 3, 6, 4, 3, 3, 2, 3, 4, 3, 4, 2, 3, 3, 5, 4, 4, 7, 1, 2, 5, 1, 5, 7, 4, 2, 3, 7, 4, 7, 2, 4, 7, 4, 4, 5, 2, 5, 8, 4, 3, 3, 5, 2, 8, 5, 4, 3, 10, 7, 8, 2, 3, 5, 5, 3, 6, 3, 3, 14, 4, 3, 12, 3, 7, 7, 5, 6, 8, 7, 5, 9, 9, 4, 4, 3, 6, 10, 8]

cp's OEIS Frontend

A220431 Number of ways to write n=x+y (x>0, y>0) with 3x-1, 3x+1 and xy-1 all prime.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	2
7	2
8	2
9	3
10	2
11	2
12	3
13	2
14	2
15	3
16	3
17	2
18	3
19	2
20	2
21	6
22	1
23	3
24	6
25	4
26	3
27	3
28	2
29	3
30	4
31	3
32	4
33	2
34	3
35	3
36	5
37	4
38	4
39	7
40	1
41	2
42	5
43	1
44	5
45	7
46	4
47	2
48	3
49	7
50	4
51	7
52	2
53	4
54	7
55	4
56	4
57	5
58	2
59	5
60	8
61	4
62	3
63	3
64	5
65	2
66	8
67	5
68	4
69	3
70	10
71	7
72	8
73	2
74	3
75	5
76	5
77	3
78	6
79	3
80	3
81	14
82	4
83	3
84	12
85	3
86	7
87	7
88	5
89	6
90	8
91	7
92	5
93	9
94	9
95	4
96	4
97	3
98	6
99	10
100	8

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	2
7	2
8	2
9	3
10	2
11	2
12	3
13	2
14	2
15	3
16	3
17	2
18	3
19	2
20	2
21	6
22	1
23	3
24	6
25	4
26	3
27	3
28	2
29	3
30	4
31	3
32	4
33	2
34	3
35	3
36	5
37	4
38	4
39	7
40	1
41	2
42	5
43	1
44	5
45	7
46	4
47	2
48	3
49	7
50	4
51	7
52	2
53	4
54	7
55	4
56	4
57	5
58	2
59	5
60	8
61	4
62	3
63	3
64	5
65	2
66	8
67	5
68	4
69	3
70	10
71	7
72	8
73	2
74	3
75	5
76	5
77	3
78	6
79	3
80	3
81	14
82	4
83	3
84	12
85	3
86	7
87	7
88	5
89	6
90	8
91	7
92	5
93	9
94	9
95	4
96	4
97	3
98	6
99	10
100	8

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	2
7	2
8	2
9	3
10	2
11	2
12	3
13	2
14	2
15	3
16	3
17	2
18	3
19	2
20	2
21	6
22	1
23	3
24	6
25	4
26	3
27	3
28	2
29	3
30	4
31	3
32	4
33	2
34	3
35	3
36	5
37	4
38	4
39	7
40	1
41	2
42	5
43	1
44	5
45	7
46	4
47	2
48	3
49	7
50	4
51	7
52	2
53	4
54	7
55	4
56	4
57	5
58	2
59	5
60	8
61	4
62	3
63	3
64	5
65	2
66	8
67	5
68	4
69	3
70	10
71	7
72	8
73	2
74	3
75	5
76	5
77	3
78	6
79	3
80	3
81	14
82	4
83	3
84	12
85	3
86	7
87	7
88	5
89	6
90	8
91	7
92	5
93	9
94	9
95	4
96	4
97	3
98	6
99	10
100	8