A179372 - cp's OEIS frontend

A179372 a(1) = 1; a(n) = smallest positive integer not already used which has a prime signature different from a(n-1), a(n-1)+1 and a(n-1)-1.

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

[1, 4, 6, 8, 10, 12, 9, 2, 14, 16, 18, 15, 3, 20, 24, 21, 5, 27, 7, 25, 11, 30, 22, 28, 26, 13, 32, 36, 40, 42, 33, 17, 34, 19, 35, 23, 44, 38, 45, 29, 39, 31, 46, 48, 50, 37, 49, 41, 51, 43, 54, 52, 56, 47, 60, 55, 53, 57, 59, 63, 61, 64, 66, 68, 70, 72, 58, 75, 67, 62, 78, 76]

cp's OEIS Frontend

A179372 a(1) = 1; a(n) = smallest positive integer not already used which has a prime signature different from a(n-1), a(n-1)+1 and a(n-1)-1.

Table of values

List of values

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

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

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