A065561 - cp's OEIS frontend

A065561 a(1) = 1; for n >= 2, a(n) = (d(n)-1)-th highest positive integer that equals no a(k), 1 <= k < n, where d(n) is the number of positive divisors of n, A000005(n).

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

[1, 2, 3, 5, 4, 8, 6, 10, 9, 12, 7, 16, 11, 15, 17, 19, 13, 22, 14, 24, 21, 23, 18, 30, 25, 27, 28, 32, 20, 36, 26, 35, 33, 34, 37, 43, 29, 39, 40, 46, 31, 48, 38, 47, 49, 44, 41, 56, 45, 53, 51, 55, 42, 60, 54, 62, 57, 58, 50, 70, 52, 63, 66, 68, 64, 72, 59, 71, 67, 76, 61, 82]

cp's OEIS Frontend

A065561 a(1) = 1; for n >= 2, a(n) = (d(n)-1)-th highest positive integer that equals no a(k), 1 <= k < n, where d(n) is the number of positive divisors of n, A000005(n).

Table of values

List of values

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

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

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