A208243 - cp's OEIS frontend

A208243 Number of ways to write 2n-1 = p+q, where p is a prime, and both q and q+2 are practical numbers (A005153).

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

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

cp's OEIS Frontend

A208243 Number of ways to write 2n-1 = p+q, where p is a prime, and both q and q+2 are practical numbers (A005153).

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

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

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