A354687 - cp's OEIS frontend

A354687 a(1) = 1; for n > 1, a(n) is the smallest positive number that has not yet appeared that shares a factor with a(n-1) and the difference | a(n) - a(n-1) | is distinct from all previous differences.

n	a(n)
1	1
2	2
3	4
4	8
5	14
6	6
7	3
8	12
9	22
10	10
11	5
12	20
13	34
14	16
15	32
16	52
17	13
18	26
19	48
20	15
21	36
22	9
23	33
24	44
25	18
26	46
27	23
28	69
29	21
30	28
31	58
32	24
33	56
34	7
35	42
36	78
37	27
38	72
39	30
40	55
41	11
42	66
43	104
44	38
45	19
46	76
47	116
48	29
49	87
50	141
51	39
52	91
53	35
54	85
55	17
56	102
57	40
58	100
59	25
60	90
61	153
62	45
63	114
64	50
65	120
66	192
67	51
68	68
69	142
70	54
71	130
72	208
73	60

[1, 2, 4, 8, 14, 6, 3, 12, 22, 10, 5, 20, 34, 16, 32, 52, 13, 26, 48, 15, 36, 9, 33, 44, 18, 46, 23, 69, 21, 28, 58, 24, 56, 7, 42, 78, 27, 72, 30, 55, 11, 66, 104, 38, 19, 76, 116, 29, 87, 141, 39, 91, 35, 85, 17, 102, 40, 100, 25, 90, 153, 45, 114, 50, 120, 192, 51, 68, 142, 54, 130, 208, 60]

cp's OEIS Frontend

A354687 a(1) = 1; for n > 1, a(n) is the smallest positive number that has not yet appeared that shares a factor with a(n-1) and the difference | a(n) - a(n-1) | is distinct from all previous differences.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	8
5	14
6	6
7	3
8	12
9	22
10	10
11	5
12	20
13	34
14	16
15	32
16	52
17	13
18	26
19	48
20	15
21	36
22	9
23	33
24	44
25	18
26	46
27	23
28	69
29	21
30	28
31	58
32	24
33	56
34	7
35	42
36	78
37	27
38	72
39	30
40	55
41	11
42	66
43	104
44	38
45	19
46	76
47	116
48	29
49	87
50	141
51	39
52	91
53	35
54	85
55	17
56	102
57	40
58	100
59	25
60	90
61	153
62	45
63	114
64	50
65	120
66	192
67	51
68	68
69	142
70	54
71	130
72	208
73	60

n	a(n)
1	1
2	2
3	4
4	8
5	14
6	6
7	3
8	12
9	22
10	10
11	5
12	20
13	34
14	16
15	32
16	52
17	13
18	26
19	48
20	15
21	36
22	9
23	33
24	44
25	18
26	46
27	23
28	69
29	21
30	28
31	58
32	24
33	56
34	7
35	42
36	78
37	27
38	72
39	30
40	55
41	11
42	66
43	104
44	38
45	19
46	76
47	116
48	29
49	87
50	141
51	39
52	91
53	35
54	85
55	17
56	102
57	40
58	100
59	25
60	90
61	153
62	45
63	114
64	50
65	120
66	192
67	51
68	68
69	142
70	54
71	130
72	208
73	60

n	a(n)
1	1
2	2
3	4
4	8
5	14
6	6
7	3
8	12
9	22
10	10
11	5
12	20
13	34
14	16
15	32
16	52
17	13
18	26
19	48
20	15
21	36
22	9
23	33
24	44
25	18
26	46
27	23
28	69
29	21
30	28
31	58
32	24
33	56
34	7
35	42
36	78
37	27
38	72
39	30
40	55
41	11
42	66
43	104
44	38
45	19
46	76
47	116
48	29
49	87
50	141
51	39
52	91
53	35
54	85
55	17
56	102
57	40
58	100
59	25
60	90
61	153
62	45
63	114
64	50
65	120
66	192
67	51
68	68
69	142
70	54
71	130
72	208
73	60