A356430 - cp's OEIS frontend

A356430 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number not occurring earlier that shares a factor with the number of divisors of a(n-1).

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	8
7	10
8	12
9	9
10	15
11	14
12	16
13	5
14	18
15	20
16	21
17	22
18	24
19	26
20	28
21	27
22	30
23	32
24	33
25	34
26	36
27	39
28	38
29	40
30	42
31	44
32	45
33	46
34	48
35	25
36	51
37	50
38	52
39	54
40	56
41	58
42	60
43	57
44	62
45	64
46	7
47	66
48	68
49	63
50	69
51	70
52	72
53	74
54	76
55	75
56	78
57	80
58	35
59	82
60	84
61	81
62	55
63	86
64	88
65	90
66	87
67	92
68	93
69	94
70	96
71	98
72	99
73	100
74	102
75	104

[1, 2, 4, 3, 6, 8, 10, 12, 9, 15, 14, 16, 5, 18, 20, 21, 22, 24, 26, 28, 27, 30, 32, 33, 34, 36, 39, 38, 40, 42, 44, 45, 46, 48, 25, 51, 50, 52, 54, 56, 58, 60, 57, 62, 64, 7, 66, 68, 63, 69, 70, 72, 74, 76, 75, 78, 80, 35, 82, 84, 81, 55, 86, 88, 90, 87, 92, 93, 94, 96, 98, 99, 100, 102, 104]

cp's OEIS Frontend

A356430 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number not occurring earlier that shares a factor with the number of divisors of a(n-1).

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	8
7	10
8	12
9	9
10	15
11	14
12	16
13	5
14	18
15	20
16	21
17	22
18	24
19	26
20	28
21	27
22	30
23	32
24	33
25	34
26	36
27	39
28	38
29	40
30	42
31	44
32	45
33	46
34	48
35	25
36	51
37	50
38	52
39	54
40	56
41	58
42	60
43	57
44	62
45	64
46	7
47	66
48	68
49	63
50	69
51	70
52	72
53	74
54	76
55	75
56	78
57	80
58	35
59	82
60	84
61	81
62	55
63	86
64	88
65	90
66	87
67	92
68	93
69	94
70	96
71	98
72	99
73	100
74	102
75	104

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	8
7	10
8	12
9	9
10	15
11	14
12	16
13	5
14	18
15	20
16	21
17	22
18	24
19	26
20	28
21	27
22	30
23	32
24	33
25	34
26	36
27	39
28	38
29	40
30	42
31	44
32	45
33	46
34	48
35	25
36	51
37	50
38	52
39	54
40	56
41	58
42	60
43	57
44	62
45	64
46	7
47	66
48	68
49	63
50	69
51	70
52	72
53	74
54	76
55	75
56	78
57	80
58	35
59	82
60	84
61	81
62	55
63	86
64	88
65	90
66	87
67	92
68	93
69	94
70	96
71	98
72	99
73	100
74	102
75	104

n	a(n)
1	1
2	2
3	4
4	3
5	6
6	8
7	10
8	12
9	9
10	15
11	14
12	16
13	5
14	18
15	20
16	21
17	22
18	24
19	26
20	28
21	27
22	30
23	32
24	33
25	34
26	36
27	39
28	38
29	40
30	42
31	44
32	45
33	46
34	48
35	25
36	51
37	50
38	52
39	54
40	56
41	58
42	60
43	57
44	62
45	64
46	7
47	66
48	68
49	63
50	69
51	70
52	72
53	74
54	76
55	75
56	78
57	80
58	35
59	82
60	84
61	81
62	55
63	86
64	88
65	90
66	87
67	92
68	93
69	94
70	96
71	98
72	99
73	100
74	102
75	104