A185091 - cp's OEIS frontend

A185091 The smallest positive noncomposite q such that 2n-1 = 2p+q for some positive noncomposite p.

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

[1, 1, 1, 3, 1, 3, 1, 3, 5, 7, 1, 3, 1, 3, 5, 7, 1, 3, 1, 3, 5, 7, 1, 3, 5, 7, 17, 11, 1, 3, 1, 3, 5, 7, 13, 11, 1, 3, 5, 7, 1, 3, 1, 3, 5, 7, 1, 3, 5, 7, 17, 11, 1, 3, 5, 7, 29, 11, 1, 3, 1, 3, 5, 7, 13, 11, 1, 3, 5, 7, 1, 3, 1, 3, 5, 7, 13, 11, 1, 3, 5, 7, 1, 3, 5, 7, 17, 11, 1, 3, 5, 7, 29]

cp's OEIS Frontend

A185091 The smallest positive noncomposite q such that 2n-1 = 2p+q for some positive noncomposite p.

Table of values

List of values

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

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

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