A091182 - cp's OEIS frontend

A091182 Number of ways to write n = x + y (x >= y > 0) with xy - 1 and xy + 1 both prime.

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

[0, 0, 0, 1, 2, 0, 2, 1, 1, 0, 2, 0, 3, 0, 0, 1, 4, 1, 2, 0, 1, 1, 3, 1, 1, 0, 2, 2, 3, 0, 6, 3, 1, 1, 1, 1, 3, 4, 3, 0, 3, 1, 4, 2, 0, 1, 4, 1, 4, 1, 1, 3, 7, 0, 1, 1, 2, 1, 4, 0, 3, 2, 3, 4, 1, 0, 9, 2, 2, 1, 5, 1, 6, 1, 0, 3, 6, 1, 5, 0, 2, 3, 7, 1, 1, 2, 2]

cp's OEIS Frontend

A091182 Number of ways to write n = x + y (x >= y > 0) with xy - 1 and xy + 1 both prime.

Table of values

List of values

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

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

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