A384045 - cp's OEIS frontend

A384045 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest unused positive number that shares a factor with a(n-1) if it is greater than it, else it is coprime to a(n-1) if it is less than it.

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	5
7	10
8	7
9	14
10	9
11	8
12	12
13	11
14	22
15	13
16	26
17	15
18	18
19	17
20	16
21	20
22	19
23	38
24	21
25	24
26	23
27	46
28	25
29	30
30	29
31	27
32	33
33	28
34	32
35	31
36	62
37	35
38	34
39	36
40	39
41	37
42	74
43	41
44	40
45	42
46	44
47	43
48	86
49	45
50	48
51	47
52	94
53	49
54	56
55	51
56	50
57	52
58	54
59	53
60	106
61	55
62	60
63	59
64	57
65	63
66	58
67	64
68	61

[1, 2, 4, 3, 6, 5, 10, 7, 14, 9, 8, 12, 11, 22, 13, 26, 15, 18, 17, 16, 20, 19, 38, 21, 24, 23, 46, 25, 30, 29, 27, 33, 28, 32, 31, 62, 35, 34, 36, 39, 37, 74, 41, 40, 42, 44, 43, 86, 45, 48, 47, 94, 49, 56, 51, 50, 52, 54, 53, 106, 55, 60, 59, 57, 63, 58, 64, 61]

cp's OEIS Frontend

A384045 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest unused positive number that shares a factor with a(n-1) if it is greater than it, else it is coprime to a(n-1) if it is less than it.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	5
7	10
8	7
9	14
10	9
11	8
12	12
13	11
14	22
15	13
16	26
17	15
18	18
19	17
20	16
21	20
22	19
23	38
24	21
25	24
26	23
27	46
28	25
29	30
30	29
31	27
32	33
33	28
34	32
35	31
36	62
37	35
38	34
39	36
40	39
41	37
42	74
43	41
44	40
45	42
46	44
47	43
48	86
49	45
50	48
51	47
52	94
53	49
54	56
55	51
56	50
57	52
58	54
59	53
60	106
61	55
62	60
63	59
64	57
65	63
66	58
67	64
68	61

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	5
7	10
8	7
9	14
10	9
11	8
12	12
13	11
14	22
15	13
16	26
17	15
18	18
19	17
20	16
21	20
22	19
23	38
24	21
25	24
26	23
27	46
28	25
29	30
30	29
31	27
32	33
33	28
34	32
35	31
36	62
37	35
38	34
39	36
40	39
41	37
42	74
43	41
44	40
45	42
46	44
47	43
48	86
49	45
50	48
51	47
52	94
53	49
54	56
55	51
56	50
57	52
58	54
59	53
60	106
61	55
62	60
63	59
64	57
65	63
66	58
67	64
68	61

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	5
7	10
8	7
9	14
10	9
11	8
12	12
13	11
14	22
15	13
16	26
17	15
18	18
19	17
20	16
21	20
22	19
23	38
24	21
25	24
26	23
27	46
28	25
29	30
30	29
31	27
32	33
33	28
34	32
35	31
36	62
37	35
38	34
39	36
40	39
41	37
42	74
43	41
44	40
45	42
46	44
47	43
48	86
49	45
50	48
51	47
52	94
53	49
54	56
55	51
56	50
57	52
58	54
59	53
60	106
61	55
62	60
63	59
64	57
65	63
66	58
67	64
68	61