A209312 - cp's OEIS frontend

A209312 Number of practical numbers p with n-p and n+p both prime or both practical.

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

[0, 0, 1, 2, 2, 2, 2, 1, 2, 3, 2, 4, 1, 2, 3, 3, 3, 4, 2, 4, 3, 4, 3, 6, 3, 2, 3, 4, 4, 6, 3, 5, 3, 4, 5, 8, 3, 2, 5, 5, 4, 7, 4, 7, 4, 2, 4, 11, 3, 1, 4, 7, 4, 7, 6, 7, 3, 4, 5, 12, 3, 2, 4, 8, 7, 8, 5, 9, 4, 2, 6, 14, 5, 2, 6, 7, 7, 9, 5, 9, 4, 4, 5, 14, 8, 2, 5, 8, 7, 10, 6, 9, 6, 2, 8, 15, 5, 3, 5, 8]

cp's OEIS Frontend

A209312 Number of practical numbers p with n-p and n+p both prime or both practical.

Table of values

List of values

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

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

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