A204142 - cp's OEIS frontend

A204142 a(1)=1 and for n>1, a(n) equals the smallest prime greater than a(n-1) of the form a(i)*a(j)+2 for some i, j < n.

n	a(n)
1	1
2	3
3	5
4	7
5	11
6	13
7	17
8	19
9	23
10	37
11	41
12	43
13	53
14	59
15	61
16	67
17	71
18	73
19	79
20	97
21	113
22	131
23	163
24	179
25	181
26	211
27	223
28	239
29	241
30	293
31	307
32	337
33	367
34	373
35	397
36	409
37	439
38	487
39	491
40	499
41	631
42	673
43	691
44	719
45	733
46	739
47	769
48	853
49	881
50	883
51	907
52	919
53	991

[1, 3, 5, 7, 11, 13, 17, 19, 23, 37, 41, 43, 53, 59, 61, 67, 71, 73, 79, 97, 113, 131, 163, 179, 181, 211, 223, 239, 241, 293, 307, 337, 367, 373, 397, 409, 439, 487, 491, 499, 631, 673, 691, 719, 733, 739, 769, 853, 881, 883, 907, 919, 991]

cp's OEIS Frontend

A204142 a(1)=1 and for n>1, a(n) equals the smallest prime greater than a(n-1) of the form a(i)*a(j)+2 for some i, j < n.

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	7
5	11
6	13
7	17
8	19
9	23
10	37
11	41
12	43
13	53
14	59
15	61
16	67
17	71
18	73
19	79
20	97
21	113
22	131
23	163
24	179
25	181
26	211
27	223
28	239
29	241
30	293
31	307
32	337
33	367
34	373
35	397
36	409
37	439
38	487
39	491
40	499
41	631
42	673
43	691
44	719
45	733
46	739
47	769
48	853
49	881
50	883
51	907
52	919
53	991

n	a(n)
1	1
2	3
3	5
4	7
5	11
6	13
7	17
8	19
9	23
10	37
11	41
12	43
13	53
14	59
15	61
16	67
17	71
18	73
19	79
20	97
21	113
22	131
23	163
24	179
25	181
26	211
27	223
28	239
29	241
30	293
31	307
32	337
33	367
34	373
35	397
36	409
37	439
38	487
39	491
40	499
41	631
42	673
43	691
44	719
45	733
46	739
47	769
48	853
49	881
50	883
51	907
52	919
53	991

n	a(n)
1	1
2	3
3	5
4	7
5	11
6	13
7	17
8	19
9	23
10	37
11	41
12	43
13	53
14	59
15	61
16	67
17	71
18	73
19	79
20	97
21	113
22	131
23	163
24	179
25	181
26	211
27	223
28	239
29	241
30	293
31	307
32	337
33	367
34	373
35	397
36	409
37	439
38	487
39	491
40	499
41	631
42	673
43	691
44	719
45	733
46	739
47	769
48	853
49	881
50	883
51	907
52	919
53	991