A351626 - cp's OEIS frontend

A351626 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number that has not appeared that shares a factor with both the largest and second largest value of all previous terms.

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	10
7	12
8	14
9	16
10	18
11	20
12	15
13	22
14	24
15	26
16	28
17	30
18	21
19	32
20	34
21	36
22	38
23	40
24	42
25	35
26	44
27	33
28	46
29	48
30	50
31	45
32	52
33	54
34	39
35	56
36	58
37	60
38	62
39	64
40	66
41	68
42	51
43	70
44	72
45	63
46	74
47	76
48	78
49	57
50	80
51	65
52	75
53	82
54	84
55	86
56	88
57	90
58	55
59	92
60	69
61	94
62	96
63	98
64	100
65	102
66	85
67	104
68	106
69	108
70	110
71	99
72	105
73	112
74	77

[1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 15, 22, 24, 26, 28, 30, 21, 32, 34, 36, 38, 40, 42, 35, 44, 33, 46, 48, 50, 45, 52, 54, 39, 56, 58, 60, 62, 64, 66, 68, 51, 70, 72, 63, 74, 76, 78, 57, 80, 65, 75, 82, 84, 86, 88, 90, 55, 92, 69, 94, 96, 98, 100, 102, 85, 104, 106, 108, 110, 99, 105, 112, 77]

cp's OEIS Frontend

A351626 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number that has not appeared that shares a factor with both the largest and second largest value of all previous terms.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	10
7	12
8	14
9	16
10	18
11	20
12	15
13	22
14	24
15	26
16	28
17	30
18	21
19	32
20	34
21	36
22	38
23	40
24	42
25	35
26	44
27	33
28	46
29	48
30	50
31	45
32	52
33	54
34	39
35	56
36	58
37	60
38	62
39	64
40	66
41	68
42	51
43	70
44	72
45	63
46	74
47	76
48	78
49	57
50	80
51	65
52	75
53	82
54	84
55	86
56	88
57	90
58	55
59	92
60	69
61	94
62	96
63	98
64	100
65	102
66	85
67	104
68	106
69	108
70	110
71	99
72	105
73	112
74	77

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	10
7	12
8	14
9	16
10	18
11	20
12	15
13	22
14	24
15	26
16	28
17	30
18	21
19	32
20	34
21	36
22	38
23	40
24	42
25	35
26	44
27	33
28	46
29	48
30	50
31	45
32	52
33	54
34	39
35	56
36	58
37	60
38	62
39	64
40	66
41	68
42	51
43	70
44	72
45	63
46	74
47	76
48	78
49	57
50	80
51	65
52	75
53	82
54	84
55	86
56	88
57	90
58	55
59	92
60	69
61	94
62	96
63	98
64	100
65	102
66	85
67	104
68	106
69	108
70	110
71	99
72	105
73	112
74	77

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	10
7	12
8	14
9	16
10	18
11	20
12	15
13	22
14	24
15	26
16	28
17	30
18	21
19	32
20	34
21	36
22	38
23	40
24	42
25	35
26	44
27	33
28	46
29	48
30	50
31	45
32	52
33	54
34	39
35	56
36	58
37	60
38	62
39	64
40	66
41	68
42	51
43	70
44	72
45	63
46	74
47	76
48	78
49	57
50	80
51	65
52	75
53	82
54	84
55	86
56	88
57	90
58	55
59	92
60	69
61	94
62	96
63	98
64	100
65	102
66	85
67	104
68	106
69	108
70	110
71	99
72	105
73	112
74	77