A209253 - cp's OEIS frontend

A209253 Number of ways to write 2n-1 as the sum of a Sophie Germain prime and a practical number.

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

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

cp's OEIS Frontend

A209253 Number of ways to write 2n-1 as the sum of a Sophie Germain prime and a practical number.

Table of values

List of values

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

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

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