A103683 - cp's OEIS frontend

A103683 a(1)=1, a(2)=2, a(3)=3, a(n) = smallest positive integer not occurring earlier in sequence and coprime to a(n-1), a(n-2) and a(n-3).

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	4
7	9
8	11
9	13
10	8
11	15
12	17
13	19
14	14
15	23
16	25
17	27
18	16
19	29
20	31
21	21
22	10
23	37
24	41
25	33
26	20
27	43
28	47
29	39
30	22
31	35
32	53
33	51
34	26
35	49
36	55
37	57
38	32
39	59
40	61
41	45
42	28
43	67
44	71
45	65
46	6
47	73
48	77
49	79
50	12
51	83
52	85
53	89
54	18
55	91
56	95
57	97
58	24
59	101
60	103
61	107
62	30
63	109
64	113
65	119
66	36
67	115
68	121
69	127
70	34

[1, 2, 3, 5, 7, 4, 9, 11, 13, 8, 15, 17, 19, 14, 23, 25, 27, 16, 29, 31, 21, 10, 37, 41, 33, 20, 43, 47, 39, 22, 35, 53, 51, 26, 49, 55, 57, 32, 59, 61, 45, 28, 67, 71, 65, 6, 73, 77, 79, 12, 83, 85, 89, 18, 91, 95, 97, 24, 101, 103, 107, 30, 109, 113, 119, 36, 115, 121, 127, 34]

cp's OEIS Frontend

A103683 a(1)=1, a(2)=2, a(3)=3, a(n) = smallest positive integer not occurring earlier in sequence and coprime to a(n-1), a(n-2) and a(n-3).

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	4
7	9
8	11
9	13
10	8
11	15
12	17
13	19
14	14
15	23
16	25
17	27
18	16
19	29
20	31
21	21
22	10
23	37
24	41
25	33
26	20
27	43
28	47
29	39
30	22
31	35
32	53
33	51
34	26
35	49
36	55
37	57
38	32
39	59
40	61
41	45
42	28
43	67
44	71
45	65
46	6
47	73
48	77
49	79
50	12
51	83
52	85
53	89
54	18
55	91
56	95
57	97
58	24
59	101
60	103
61	107
62	30
63	109
64	113
65	119
66	36
67	115
68	121
69	127
70	34

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	4
7	9
8	11
9	13
10	8
11	15
12	17
13	19
14	14
15	23
16	25
17	27
18	16
19	29
20	31
21	21
22	10
23	37
24	41
25	33
26	20
27	43
28	47
29	39
30	22
31	35
32	53
33	51
34	26
35	49
36	55
37	57
38	32
39	59
40	61
41	45
42	28
43	67
44	71
45	65
46	6
47	73
48	77
49	79
50	12
51	83
52	85
53	89
54	18
55	91
56	95
57	97
58	24
59	101
60	103
61	107
62	30
63	109
64	113
65	119
66	36
67	115
68	121
69	127
70	34

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	4
7	9
8	11
9	13
10	8
11	15
12	17
13	19
14	14
15	23
16	25
17	27
18	16
19	29
20	31
21	21
22	10
23	37
24	41
25	33
26	20
27	43
28	47
29	39
30	22
31	35
32	53
33	51
34	26
35	49
36	55
37	57
38	32
39	59
40	61
41	45
42	28
43	67
44	71
45	65
46	6
47	73
48	77
49	79
50	12
51	83
52	85
53	89
54	18
55	91
56	95
57	97
58	24
59	101
60	103
61	107
62	30
63	109
64	113
65	119
66	36
67	115
68	121
69	127
70	34