A245603 - cp's OEIS frontend

A245603 Permutation of natural numbers: a(1) = 1; thereafter, if n is k-th number with an odd number of prime divisors (counted with multiplicity) [i.e., n = A026424(k)], a(n) = 2a(k), otherwise, when n is k-th number > 1 with an even number of prime divisors [i.e., n = A028260(1+k)], a(n) = 1+(2a(k)).

n	a(n)
1	1
2	2
3	4
4	3
5	8
6	5
7	6
8	16
9	9
10	7
11	10
12	12
13	32
14	17
15	11
16	13
17	18
18	14
19	20
20	24
21	33
22	19
23	64
24	15
25	21
26	25
27	34
28	22
29	26
30	36
31	28
32	40
33	65
34	35
35	23
36	27
37	48
38	37
39	29
40	41
41	66
42	38
43	128
44	30
45	42
46	49
47	50
48	68
49	67
50	44
51	39
52	52
53	72
54	129
55	31
56	43
57	51
58	69
59	56
60	45
61	80
62	53
63	130
64	73
65	57
66	70
67	46
68	54
69	81
70	96
71	74
72	58
73	82
74	131
75	132
76	76
77	71
78	256
79	60

[1, 2, 4, 3, 8, 5, 6, 16, 9, 7, 10, 12, 32, 17, 11, 13, 18, 14, 20, 24, 33, 19, 64, 15, 21, 25, 34, 22, 26, 36, 28, 40, 65, 35, 23, 27, 48, 37, 29, 41, 66, 38, 128, 30, 42, 49, 50, 68, 67, 44, 39, 52, 72, 129, 31, 43, 51, 69, 56, 45, 80, 53, 130, 73, 57, 70, 46, 54, 81, 96, 74, 58, 82, 131, 132, 76, 71, 256, 60]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	3
5	8
6	5
7	6
8	16
9	9
10	7
11	10
12	12
13	32
14	17
15	11
16	13
17	18
18	14
19	20
20	24
21	33
22	19
23	64
24	15
25	21
26	25
27	34
28	22
29	26
30	36
31	28
32	40
33	65
34	35
35	23
36	27
37	48
38	37
39	29
40	41
41	66
42	38
43	128
44	30
45	42
46	49
47	50
48	68
49	67
50	44
51	39
52	52
53	72
54	129
55	31
56	43
57	51
58	69
59	56
60	45
61	80
62	53
63	130
64	73
65	57
66	70
67	46
68	54
69	81
70	96
71	74
72	58
73	82
74	131
75	132
76	76
77	71
78	256
79	60

n	a(n)
1	1
2	2
3	4
4	3
5	8
6	5
7	6
8	16
9	9
10	7
11	10
12	12
13	32
14	17
15	11
16	13
17	18
18	14
19	20
20	24
21	33
22	19
23	64
24	15
25	21
26	25
27	34
28	22
29	26
30	36
31	28
32	40
33	65
34	35
35	23
36	27
37	48
38	37
39	29
40	41
41	66
42	38
43	128
44	30
45	42
46	49
47	50
48	68
49	67
50	44
51	39
52	52
53	72
54	129
55	31
56	43
57	51
58	69
59	56
60	45
61	80
62	53
63	130
64	73
65	57
66	70
67	46
68	54
69	81
70	96
71	74
72	58
73	82
74	131
75	132
76	76
77	71
78	256
79	60

n	a(n)
1	1
2	2
3	4
4	3
5	8
6	5
7	6
8	16
9	9
10	7
11	10
12	12
13	32
14	17
15	11
16	13
17	18
18	14
19	20
20	24
21	33
22	19
23	64
24	15
25	21
26	25
27	34
28	22
29	26
30	36
31	28
32	40
33	65
34	35
35	23
36	27
37	48
38	37
39	29
40	41
41	66
42	38
43	128
44	30
45	42
46	49
47	50
48	68
49	67
50	44
51	39
52	52
53	72
54	129
55	31
56	43
57	51
58	69
59	56
60	45
61	80
62	53
63	130
64	73
65	57
66	70
67	46
68	54
69	81
70	96
71	74
72	58
73	82
74	131
75	132
76	76
77	71
78	256
79	60