A085090 - cp's OEIS frontend

A085090 If 2n-1 is prime then a(n) = 2n-1, otherwise a(n) = 0.

n	a(n)
1	0
2	3
3	5
4	7
5	0
6	11
7	13
8	0
9	17
10	19
11	0
12	23
13	0
14	0
15	29
16	31
17	0
18	0
19	37
20	0
21	41
22	43
23	0
24	47
25	0
26	0
27	53
28	0
29	0
30	59
31	61
32	0
33	0
34	67
35	0
36	71
37	73
38	0
39	0
40	79
41	0
42	83
43	0
44	0
45	89
46	0
47	0
48	0
49	97
50	0
51	101
52	103
53	0
54	107
55	109
56	0
57	113
58	0
59	0
60	0
61	0
62	0
63	0
64	127
65	0
66	131
67	0
68	0
69	137
70	139
71	0
72	0
73	0
74	0
75	149
76	151
77	0
78	0
79	157
80	0
81	0
82	163

[0, 3, 5, 7, 0, 11, 13, 0, 17, 19, 0, 23, 0, 0, 29, 31, 0, 0, 37, 0, 41, 43, 0, 47, 0, 0, 53, 0, 0, 59, 61, 0, 0, 67, 0, 71, 73, 0, 0, 79, 0, 83, 0, 0, 89, 0, 0, 0, 97, 0, 101, 103, 0, 107, 109, 0, 113, 0, 0, 0, 0, 0, 0, 127, 0, 131, 0, 0, 137, 139, 0, 0, 0, 0, 149, 151, 0, 0, 157, 0, 0, 163]

cp's OEIS Frontend

A085090 If 2n-1 is prime then a(n) = 2n-1, otherwise a(n) = 0.

Table of values

List of values

n	a(n)
1	0
2	3
3	5
4	7
5	0
6	11
7	13
8	0
9	17
10	19
11	0
12	23
13	0
14	0
15	29
16	31
17	0
18	0
19	37
20	0
21	41
22	43
23	0
24	47
25	0
26	0
27	53
28	0
29	0
30	59
31	61
32	0
33	0
34	67
35	0
36	71
37	73
38	0
39	0
40	79
41	0
42	83
43	0
44	0
45	89
46	0
47	0
48	0
49	97
50	0
51	101
52	103
53	0
54	107
55	109
56	0
57	113
58	0
59	0
60	0
61	0
62	0
63	0
64	127
65	0
66	131
67	0
68	0
69	137
70	139
71	0
72	0
73	0
74	0
75	149
76	151
77	0
78	0
79	157
80	0
81	0
82	163

n	a(n)
1	0
2	3
3	5
4	7
5	0
6	11
7	13
8	0
9	17
10	19
11	0
12	23
13	0
14	0
15	29
16	31
17	0
18	0
19	37
20	0
21	41
22	43
23	0
24	47
25	0
26	0
27	53
28	0
29	0
30	59
31	61
32	0
33	0
34	67
35	0
36	71
37	73
38	0
39	0
40	79
41	0
42	83
43	0
44	0
45	89
46	0
47	0
48	0
49	97
50	0
51	101
52	103
53	0
54	107
55	109
56	0
57	113
58	0
59	0
60	0
61	0
62	0
63	0
64	127
65	0
66	131
67	0
68	0
69	137
70	139
71	0
72	0
73	0
74	0
75	149
76	151
77	0
78	0
79	157
80	0
81	0
82	163

n	a(n)
1	0
2	3
3	5
4	7
5	0
6	11
7	13
8	0
9	17
10	19
11	0
12	23
13	0
14	0
15	29
16	31
17	0
18	0
19	37
20	0
21	41
22	43
23	0
24	47
25	0
26	0
27	53
28	0
29	0
30	59
31	61
32	0
33	0
34	67
35	0
36	71
37	73
38	0
39	0
40	79
41	0
42	83
43	0
44	0
45	89
46	0
47	0
48	0
49	97
50	0
51	101
52	103
53	0
54	107
55	109
56	0
57	113
58	0
59	0
60	0
61	0
62	0
63	0
64	127
65	0
66	131
67	0
68	0
69	137
70	139
71	0
72	0
73	0
74	0
75	149
76	151
77	0
78	0
79	157
80	0
81	0
82	163