A143692 - cp's OEIS frontend

A143692 Permutation of natural numbers: If n is k-th number with an odd number of prime divisors (counted with multiplicity) [i.e., n = A026424(k)], a(n) = 2k, otherwise, when n is k-th number with an even number of prime divisors [i.e., n = A028260(k)], a(n) = (2k)-1.

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

[1, 2, 4, 3, 6, 5, 8, 10, 7, 9, 12, 14, 16, 11, 13, 15, 18, 20, 22, 24, 17, 19, 26, 21, 23, 25, 28, 30, 32, 34, 36, 38, 27, 29, 31, 33, 40, 35, 37, 39, 42, 44, 46, 48, 50, 41, 52, 54, 43, 56, 45, 58, 60, 47, 49, 51, 53, 55, 62, 57, 64, 59, 66, 61, 63, 68, 70, 72, 65, 74, 76, 78]

cp's OEIS Frontend

A143692 Permutation of natural numbers: If n is k-th number with an odd number of prime divisors (counted with multiplicity) [i.e., n = A026424(k)], a(n) = 2k, otherwise, when n is k-th number with an even number of prime divisors [i.e., n = A028260(k)], a(n) = (2k)-1.

Table of values

List of values

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

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

cp's OEIS Frontend

A143692 Permutation of natural numbers: If n is k-th number with an odd number of prime divisors (counted with multiplicity) [i.e., n = A026424(k)], a(n) = 2*k, otherwise, when n is k-th number with an even number of prime divisors [i.e., n = A028260(k)], a(n) = (2*k)-1.

Table of values

List of values

A143692 Permutation of natural numbers: If n is k-th number with an odd number of prime divisors (counted with multiplicity) [i.e., n = A026424(k)], a(n) = 2k, otherwise, when n is k-th number with an even number of prime divisors [i.e., n = A028260(k)], a(n) = (2k)-1.

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