A359505 - cp's OEIS frontend

A359505 a(1)=2, a(2)=3, and for n >= 3, a(n) is calculated by considering in ascending order all products P of (distinct) terms from {a(1..n-1)} until finding one where P-1 has a prime factor not in {a(1..n-1)}, in which case a(n) is the smallest such prime factor.

n	a(n)
1	2
2	3
3	5
4	7
5	13
6	29
7	17
8	11
9	19
10	37
11	41
12	23
13	73
14	43
15	47
16	31
17	61
18	101
19	109
20	113
21	59
22	137
23	71
24	173
25	181
26	97
27	193
28	67
29	53
30	79
31	157
32	107
33	229
34	127
35	257
36	281
37	149
38	151
39	103
40	313
41	317
42	163
43	167
44	83
45	353
46	89
47	373
48	389
49	197
50	131
51	199
52	397
53	401
54	409
55	139
56	277
57	433
58	223

[2, 3, 5, 7, 13, 29, 17, 11, 19, 37, 41, 23, 73, 43, 47, 31, 61, 101, 109, 113, 59, 137, 71, 173, 181, 97, 193, 67, 53, 79, 157, 107, 229, 127, 257, 281, 149, 151, 103, 313, 317, 163, 167, 83, 353, 89, 373, 389, 197, 131, 199, 397, 401, 409, 139, 277, 433, 223]

cp's OEIS Frontend

A359505 a(1)=2, a(2)=3, and for n >= 3, a(n) is calculated by considering in ascending order all products P of (distinct) terms from {a(1..n-1)} until finding one where P-1 has a prime factor not in {a(1..n-1)}, in which case a(n) is the smallest such prime factor.

Table of values

List of values

n	a(n)
1	2
2	3
3	5
4	7
5	13
6	29
7	17
8	11
9	19
10	37
11	41
12	23
13	73
14	43
15	47
16	31
17	61
18	101
19	109
20	113
21	59
22	137
23	71
24	173
25	181
26	97
27	193
28	67
29	53
30	79
31	157
32	107
33	229
34	127
35	257
36	281
37	149
38	151
39	103
40	313
41	317
42	163
43	167
44	83
45	353
46	89
47	373
48	389
49	197
50	131
51	199
52	397
53	401
54	409
55	139
56	277
57	433
58	223

n	a(n)
1	2
2	3
3	5
4	7
5	13
6	29
7	17
8	11
9	19
10	37
11	41
12	23
13	73
14	43
15	47
16	31
17	61
18	101
19	109
20	113
21	59
22	137
23	71
24	173
25	181
26	97
27	193
28	67
29	53
30	79
31	157
32	107
33	229
34	127
35	257
36	281
37	149
38	151
39	103
40	313
41	317
42	163
43	167
44	83
45	353
46	89
47	373
48	389
49	197
50	131
51	199
52	397
53	401
54	409
55	139
56	277
57	433
58	223

n	a(n)
1	2
2	3
3	5
4	7
5	13
6	29
7	17
8	11
9	19
10	37
11	41
12	23
13	73
14	43
15	47
16	31
17	61
18	101
19	109
20	113
21	59
22	137
23	71
24	173
25	181
26	97
27	193
28	67
29	53
30	79
31	157
32	107
33	229
34	127
35	257
36	281
37	149
38	151
39	103
40	313
41	317
42	163
43	167
44	83
45	353
46	89
47	373
48	389
49	197
50	131
51	199
52	397
53	401
54	409
55	139
56	277
57	433
58	223