A081942 - cp's OEIS frontend

A081942 a(1) = 1, a(n) = smallest number greater than a(n-1) such that a(n-1)*a(n) + 1 is prime.

n	a(n)
1	1
2	2
3	3
4	4
5	7
6	10
7	13
8	24
9	25
10	28
11	34
12	37
13	40
14	43
15	46
16	51
17	56
18	60
19	67
20	70
21	79
22	84
23	87
24	94
25	105
26	106
27	120
28	126
29	130
30	133
31	136
32	147
33	148
34	151
35	156
36	161
37	162
38	163
39	166
40	171
41	176
42	177
43	184
44	190
45	193
46	204
47	208
48	211
49	228
50	234
51	239
52	242
53	248
54	252
55	256
56	262
57	265
58	270

[1, 2, 3, 4, 7, 10, 13, 24, 25, 28, 34, 37, 40, 43, 46, 51, 56, 60, 67, 70, 79, 84, 87, 94, 105, 106, 120, 126, 130, 133, 136, 147, 148, 151, 156, 161, 162, 163, 166, 171, 176, 177, 184, 190, 193, 204, 208, 211, 228, 234, 239, 242, 248, 252, 256, 262, 265, 270]

cp's OEIS Frontend

A081942 a(1) = 1, a(n) = smallest number greater than a(n-1) such that a(n-1)*a(n) + 1 is prime.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	7
6	10
7	13
8	24
9	25
10	28
11	34
12	37
13	40
14	43
15	46
16	51
17	56
18	60
19	67
20	70
21	79
22	84
23	87
24	94
25	105
26	106
27	120
28	126
29	130
30	133
31	136
32	147
33	148
34	151
35	156
36	161
37	162
38	163
39	166
40	171
41	176
42	177
43	184
44	190
45	193
46	204
47	208
48	211
49	228
50	234
51	239
52	242
53	248
54	252
55	256
56	262
57	265
58	270

n	a(n)
1	1
2	2
3	3
4	4
5	7
6	10
7	13
8	24
9	25
10	28
11	34
12	37
13	40
14	43
15	46
16	51
17	56
18	60
19	67
20	70
21	79
22	84
23	87
24	94
25	105
26	106
27	120
28	126
29	130
30	133
31	136
32	147
33	148
34	151
35	156
36	161
37	162
38	163
39	166
40	171
41	176
42	177
43	184
44	190
45	193
46	204
47	208
48	211
49	228
50	234
51	239
52	242
53	248
54	252
55	256
56	262
57	265
58	270

n	a(n)
1	1
2	2
3	3
4	4
5	7
6	10
7	13
8	24
9	25
10	28
11	34
12	37
13	40
14	43
15	46
16	51
17	56
18	60
19	67
20	70
21	79
22	84
23	87
24	94
25	105
26	106
27	120
28	126
29	130
30	133
31	136
32	147
33	148
34	151
35	156
36	161
37	162
38	163
39	166
40	171
41	176
42	177
43	184
44	190
45	193
46	204
47	208
48	211
49	228
50	234
51	239
52	242
53	248
54	252
55	256
56	262
57	265
58	270