A185191 - cp's OEIS frontend

A185191 a(n) = 2^n - second largest prime less than 2^n.

n	a(n)
2	2
3	3
4	5
5	3
6	5
7	15
8	15
9	9
10	5
11	19
12	5
13	13
14	15
15	49
16	17
17	9
18	11
19	19
20	5
21	19
22	17
23	21
24	17
25	49
26	27
27	79
28	89
29	33
30	41
31	19
32	17
33	25
34	77
35	49
36	17
37	31
38	87
39	19
40	167
41	31
42	17
43	67
44	117
45	69
46	57
47	127
48	65
49	111
50	35
51	139
52	143
53	145
54	53
55	67
56	27
57	25
58	57
59	99
60	107
61	31
62	87
63	165
64	83

[2, 3, 5, 3, 5, 15, 15, 9, 5, 19, 5, 13, 15, 49, 17, 9, 11, 19, 5, 19, 17, 21, 17, 49, 27, 79, 89, 33, 41, 19, 17, 25, 77, 49, 17, 31, 87, 19, 167, 31, 17, 67, 117, 69, 57, 127, 65, 111, 35, 139, 143, 145, 53, 67, 27, 25, 57, 99, 107, 31, 87, 165, 83]

cp's OEIS Frontend

A185191 a(n) = 2^n - second largest prime less than 2^n.

Table of values

List of values

n	a(n)
2	2
3	3
4	5
5	3
6	5
7	15
8	15
9	9
10	5
11	19
12	5
13	13
14	15
15	49
16	17
17	9
18	11
19	19
20	5
21	19
22	17
23	21
24	17
25	49
26	27
27	79
28	89
29	33
30	41
31	19
32	17
33	25
34	77
35	49
36	17
37	31
38	87
39	19
40	167
41	31
42	17
43	67
44	117
45	69
46	57
47	127
48	65
49	111
50	35
51	139
52	143
53	145
54	53
55	67
56	27
57	25
58	57
59	99
60	107
61	31
62	87
63	165
64	83

n	a(n)
2	2
3	3
4	5
5	3
6	5
7	15
8	15
9	9
10	5
11	19
12	5
13	13
14	15
15	49
16	17
17	9
18	11
19	19
20	5
21	19
22	17
23	21
24	17
25	49
26	27
27	79
28	89
29	33
30	41
31	19
32	17
33	25
34	77
35	49
36	17
37	31
38	87
39	19
40	167
41	31
42	17
43	67
44	117
45	69
46	57
47	127
48	65
49	111
50	35
51	139
52	143
53	145
54	53
55	67
56	27
57	25
58	57
59	99
60	107
61	31
62	87
63	165
64	83

n	a(n)
2	2
3	3
4	5
5	3
6	5
7	15
8	15
9	9
10	5
11	19
12	5
13	13
14	15
15	49
16	17
17	9
18	11
19	19
20	5
21	19
22	17
23	21
24	17
25	49
26	27
27	79
28	89
29	33
30	41
31	19
32	17
33	25
34	77
35	49
36	17
37	31
38	87
39	19
40	167
41	31
42	17
43	67
44	117
45	69
46	57
47	127
48	65
49	111
50	35
51	139
52	143
53	145
54	53
55	67
56	27
57	25
58	57
59	99
60	107
61	31
62	87
63	165
64	83