A103509 - cp's OEIS frontend

A103509 a(n) is the least j such that 2n+1 = 2*A000040(k) + A000040(j) for some k > 1, or 0 if no such j exists.

n	a(n)
1	0
2	0
3	0
4	2
5	3
6	2
7	3
8	2
9	3
10	4
11	6
12	2
13	3
14	2
15	3
16	4
17	6
18	2
19	3
20	2
21	3
22	4
23	6
24	2
25	3
26	4
27	7
28	5
29	6
30	2
31	3
32	2
33	3
34	4
35	6
36	5
37	6
38	2
39	3
40	4
41	12
42	2
43	3
44	2
45	3
46	4
47	6
48	2
49	3
50	4
51	7
52	5
53	6
54	2
55	3
56	4
57	10
58	5
59	6
60	2
61	3
62	2
63	3
64	4
65	6
66	5
67	6
68	2
69	3
70	4
71	12
72	2
73	3
74	2
75	3
76	4
77	6
78	5
79	6
80	2
81	3
82	4
83	18
84	2
85	3
86	4
87	7
88	5
89	6
90	2
91	3
92	4
93	10
94	5
95	6
96	15
97	7
98	2
99	3
100	4
101	12
102	2
103	3
104	2
105	3

[0, 0, 0, 2, 3, 2, 3, 2, 3, 4, 6, 2, 3, 2, 3, 4, 6, 2, 3, 2, 3, 4, 6, 2, 3, 4, 7, 5, 6, 2, 3, 2, 3, 4, 6, 5, 6, 2, 3, 4, 12, 2, 3, 2, 3, 4, 6, 2, 3, 4, 7, 5, 6, 2, 3, 4, 10, 5, 6, 2, 3, 2, 3, 4, 6, 5, 6, 2, 3, 4, 12, 2, 3, 2, 3, 4, 6, 5, 6, 2, 3, 4, 18, 2, 3, 4, 7, 5, 6, 2, 3, 4, 10, 5, 6, 15, 7, 2, 3, 4, 12, 2, 3, 2, 3]

cp's OEIS Frontend

A103509 a(n) is the least j such that 2n+1 = 2*A000040(k) + A000040(j) for some k > 1, or 0 if no such j exists.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	2
5	3
6	2
7	3
8	2
9	3
10	4
11	6
12	2
13	3
14	2
15	3
16	4
17	6
18	2
19	3
20	2
21	3
22	4
23	6
24	2
25	3
26	4
27	7
28	5
29	6
30	2
31	3
32	2
33	3
34	4
35	6
36	5
37	6
38	2
39	3
40	4
41	12
42	2
43	3
44	2
45	3
46	4
47	6
48	2
49	3
50	4
51	7
52	5
53	6
54	2
55	3
56	4
57	10
58	5
59	6
60	2
61	3
62	2
63	3
64	4
65	6
66	5
67	6
68	2
69	3
70	4
71	12
72	2
73	3
74	2
75	3
76	4
77	6
78	5
79	6
80	2
81	3
82	4
83	18
84	2
85	3
86	4
87	7
88	5
89	6
90	2
91	3
92	4
93	10
94	5
95	6
96	15
97	7
98	2
99	3
100	4
101	12
102	2
103	3
104	2
105	3

n	a(n)
1	0
2	0
3	0
4	2
5	3
6	2
7	3
8	2
9	3
10	4
11	6
12	2
13	3
14	2
15	3
16	4
17	6
18	2
19	3
20	2
21	3
22	4
23	6
24	2
25	3
26	4
27	7
28	5
29	6
30	2
31	3
32	2
33	3
34	4
35	6
36	5
37	6
38	2
39	3
40	4
41	12
42	2
43	3
44	2
45	3
46	4
47	6
48	2
49	3
50	4
51	7
52	5
53	6
54	2
55	3
56	4
57	10
58	5
59	6
60	2
61	3
62	2
63	3
64	4
65	6
66	5
67	6
68	2
69	3
70	4
71	12
72	2
73	3
74	2
75	3
76	4
77	6
78	5
79	6
80	2
81	3
82	4
83	18
84	2
85	3
86	4
87	7
88	5
89	6
90	2
91	3
92	4
93	10
94	5
95	6
96	15
97	7
98	2
99	3
100	4
101	12
102	2
103	3
104	2
105	3

n	a(n)
1	0
2	0
3	0
4	2
5	3
6	2
7	3
8	2
9	3
10	4
11	6
12	2
13	3
14	2
15	3
16	4
17	6
18	2
19	3
20	2
21	3
22	4
23	6
24	2
25	3
26	4
27	7
28	5
29	6
30	2
31	3
32	2
33	3
34	4
35	6
36	5
37	6
38	2
39	3
40	4
41	12
42	2
43	3
44	2
45	3
46	4
47	6
48	2
49	3
50	4
51	7
52	5
53	6
54	2
55	3
56	4
57	10
58	5
59	6
60	2
61	3
62	2
63	3
64	4
65	6
66	5
67	6
68	2
69	3
70	4
71	12
72	2
73	3
74	2
75	3
76	4
77	6
78	5
79	6
80	2
81	3
82	4
83	18
84	2
85	3
86	4
87	7
88	5
89	6
90	2
91	3
92	4
93	10
94	5
95	6
96	15
97	7
98	2
99	3
100	4
101	12
102	2
103	3
104	2
105	3