A251756 - cp's OEIS frontend

A251756 a(0) = 0; for n>0, a(n) is the smallest integer not already in the list with a composite common factor with a(n-1).

n	a(n)
0	0
1	4
2	8
3	12
4	6
5	18
6	9
7	27
8	36
9	16
10	20
11	10
12	30
13	15
14	45
15	54
16	24
17	28
18	14
19	42
20	21
21	63
22	72
23	32
24	40
25	44
26	22
27	66
28	33
29	99
30	81
31	90
32	48
33	52
34	26
35	78
36	39
37	117
38	108
39	56
40	60
41	50
42	25
43	75
44	100
45	64
46	68
47	34
48	102
49	51
50	153
51	126
52	70
53	35
54	105
55	84
56	76
57	38
58	114
59	57
60	171
61	135
62	120
63	80

[0, 4, 8, 12, 6, 18, 9, 27, 36, 16, 20, 10, 30, 15, 45, 54, 24, 28, 14, 42, 21, 63, 72, 32, 40, 44, 22, 66, 33, 99, 81, 90, 48, 52, 26, 78, 39, 117, 108, 56, 60, 50, 25, 75, 100, 64, 68, 34, 102, 51, 153, 126, 70, 35, 105, 84, 76, 38, 114, 57, 171, 135, 120, 80]

cp's OEIS Frontend

A251756 a(0) = 0; for n>0, a(n) is the smallest integer not already in the list with a composite common factor with a(n-1).

Table of values

List of values

n	a(n)
0	0
1	4
2	8
3	12
4	6
5	18
6	9
7	27
8	36
9	16
10	20
11	10
12	30
13	15
14	45
15	54
16	24
17	28
18	14
19	42
20	21
21	63
22	72
23	32
24	40
25	44
26	22
27	66
28	33
29	99
30	81
31	90
32	48
33	52
34	26
35	78
36	39
37	117
38	108
39	56
40	60
41	50
42	25
43	75
44	100
45	64
46	68
47	34
48	102
49	51
50	153
51	126
52	70
53	35
54	105
55	84
56	76
57	38
58	114
59	57
60	171
61	135
62	120
63	80

n	a(n)
0	0
1	4
2	8
3	12
4	6
5	18
6	9
7	27
8	36
9	16
10	20
11	10
12	30
13	15
14	45
15	54
16	24
17	28
18	14
19	42
20	21
21	63
22	72
23	32
24	40
25	44
26	22
27	66
28	33
29	99
30	81
31	90
32	48
33	52
34	26
35	78
36	39
37	117
38	108
39	56
40	60
41	50
42	25
43	75
44	100
45	64
46	68
47	34
48	102
49	51
50	153
51	126
52	70
53	35
54	105
55	84
56	76
57	38
58	114
59	57
60	171
61	135
62	120
63	80

n	a(n)
0	0
1	4
2	8
3	12
4	6
5	18
6	9
7	27
8	36
9	16
10	20
11	10
12	30
13	15
14	45
15	54
16	24
17	28
18	14
19	42
20	21
21	63
22	72
23	32
24	40
25	44
26	22
27	66
28	33
29	99
30	81
31	90
32	48
33	52
34	26
35	78
36	39
37	117
38	108
39	56
40	60
41	50
42	25
43	75
44	100
45	64
46	68
47	34
48	102
49	51
50	153
51	126
52	70
53	35
54	105
55	84
56	76
57	38
58	114
59	57
60	171
61	135
62	120
63	80