A209320 - cp's OEIS frontend

A209320 Number of ways to write 2n = p+q with p and q both prime, p+1 and q-1 both practical.

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

[0, 0, 1, 2, 3, 2, 2, 2, 2, 3, 4, 5, 3, 2, 3, 3, 5, 7, 3, 3, 4, 4, 5, 8, 4, 3, 5, 2, 4, 8, 3, 4, 6, 2, 4, 7, 3, 4, 7, 2, 4, 9, 4, 4, 9, 5, 3, 9, 3, 5, 8, 3, 4, 10, 4, 6, 8, 5, 4, 14, 2, 4, 8, 2, 6, 10, 4, 4, 7, 4, 4, 10, 5, 4, 8, 3, 4, 9, 5, 5, 7, 3, 3, 13, 6, 5, 7, 4, 2, 11, 5, 5, 9, 4, 2, 9, 3, 6, 10, 7]

cp's OEIS Frontend

A209320 Number of ways to write 2n = p+q with p and q both prime, p+1 and q-1 both practical.

Table of values

List of values

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

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

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