A347404 - cp's OEIS frontend

A347404 a(1) = 3; for n > 2, a(n) is the smallest distinct positive integer such that gcd(a(n), a(n-k)) > 1 for each divisor k of a(n) such that k < n.

n	a(n)
1	3
2	6
3	9
4	12
5	15
6	18
7	10
8	2
9	14
10	4
11	22
12	8
13	24
14	16
15	20
16	28
17	26
18	30
19	34
20	32
21	36
22	40
23	5
24	50
25	60
26	38
27	42
28	44
29	46
30	48
31	54
32	52
33	58
34	56
35	62
36	64
37	66
38	68
39	70
40	72
41	74
42	78
43	39
44	90
45	57
46	21
47	51
48	69
49	84
50	87
51	33
52	27
53	96
54	81
55	63
56	7
57	126
58	45
59	168
60	99
61	93
62	75
63	95
64	19
65	114
66	105
67	77
68	198
69	153
70	165
71	11
72	132
73	55
74	595

[3, 6, 9, 12, 15, 18, 10, 2, 14, 4, 22, 8, 24, 16, 20, 28, 26, 30, 34, 32, 36, 40, 5, 50, 60, 38, 42, 44, 46, 48, 54, 52, 58, 56, 62, 64, 66, 68, 70, 72, 74, 78, 39, 90, 57, 21, 51, 69, 84, 87, 33, 27, 96, 81, 63, 7, 126, 45, 168, 99, 93, 75, 95, 19, 114, 105, 77, 198, 153, 165, 11, 132, 55, 595]

cp's OEIS Frontend

A347404 a(1) = 3; for n > 2, a(n) is the smallest distinct positive integer such that gcd(a(n), a(n-k)) > 1 for each divisor k of a(n) such that k < n.

Table of values

List of values

n	a(n)
1	3
2	6
3	9
4	12
5	15
6	18
7	10
8	2
9	14
10	4
11	22
12	8
13	24
14	16
15	20
16	28
17	26
18	30
19	34
20	32
21	36
22	40
23	5
24	50
25	60
26	38
27	42
28	44
29	46
30	48
31	54
32	52
33	58
34	56
35	62
36	64
37	66
38	68
39	70
40	72
41	74
42	78
43	39
44	90
45	57
46	21
47	51
48	69
49	84
50	87
51	33
52	27
53	96
54	81
55	63
56	7
57	126
58	45
59	168
60	99
61	93
62	75
63	95
64	19
65	114
66	105
67	77
68	198
69	153
70	165
71	11
72	132
73	55
74	595

n	a(n)
1	3
2	6
3	9
4	12
5	15
6	18
7	10
8	2
9	14
10	4
11	22
12	8
13	24
14	16
15	20
16	28
17	26
18	30
19	34
20	32
21	36
22	40
23	5
24	50
25	60
26	38
27	42
28	44
29	46
30	48
31	54
32	52
33	58
34	56
35	62
36	64
37	66
38	68
39	70
40	72
41	74
42	78
43	39
44	90
45	57
46	21
47	51
48	69
49	84
50	87
51	33
52	27
53	96
54	81
55	63
56	7
57	126
58	45
59	168
60	99
61	93
62	75
63	95
64	19
65	114
66	105
67	77
68	198
69	153
70	165
71	11
72	132
73	55
74	595

n	a(n)
1	3
2	6
3	9
4	12
5	15
6	18
7	10
8	2
9	14
10	4
11	22
12	8
13	24
14	16
15	20
16	28
17	26
18	30
19	34
20	32
21	36
22	40
23	5
24	50
25	60
26	38
27	42
28	44
29	46
30	48
31	54
32	52
33	58
34	56
35	62
36	64
37	66
38	68
39	70
40	72
41	74
42	78
43	39
44	90
45	57
46	21
47	51
48	69
49	84
50	87
51	33
52	27
53	96
54	81
55	63
56	7
57	126
58	45
59	168
60	99
61	93
62	75
63	95
64	19
65	114
66	105
67	77
68	198
69	153
70	165
71	11
72	132
73	55
74	595