A141113 - cp's OEIS frontend

A141113 Positive integers k such that d(d(k)) divides k, where d(k) is the number of divisors of k.

n	a(n)
1	1
2	2
3	4
4	6
5	12
6	15
7	16
8	20
9	21
10	24
11	27
12	28
13	32
14	33
15	36
16	39
17	40
18	44
19	48
20	51
21	52
22	56
23	57
24	60
25	64
26	68
27	69
28	72
29	76
30	80
31	84
32	87
33	88
34	90
35	92
36	93
37	96
38	104
39	108
40	111
41	112
42	116
43	120
44	123
45	124
46	126
47	128
48	129
49	132
50	136
51	141
52	144
53	148
54	150
55	152
56	156
57	159
58	164
59	172
60	176
61	177
62	180

[1, 2, 4, 6, 12, 15, 16, 20, 21, 24, 27, 28, 32, 33, 36, 39, 40, 44, 48, 51, 52, 56, 57, 60, 64, 68, 69, 72, 76, 80, 84, 87, 88, 90, 92, 93, 96, 104, 108, 111, 112, 116, 120, 123, 124, 126, 128, 129, 132, 136, 141, 144, 148, 150, 152, 156, 159, 164, 172, 176, 177, 180]

cp's OEIS Frontend

A141113 Positive integers k such that d(d(k)) divides k, where d(k) is the number of divisors of k.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	6
5	12
6	15
7	16
8	20
9	21
10	24
11	27
12	28
13	32
14	33
15	36
16	39
17	40
18	44
19	48
20	51
21	52
22	56
23	57
24	60
25	64
26	68
27	69
28	72
29	76
30	80
31	84
32	87
33	88
34	90
35	92
36	93
37	96
38	104
39	108
40	111
41	112
42	116
43	120
44	123
45	124
46	126
47	128
48	129
49	132
50	136
51	141
52	144
53	148
54	150
55	152
56	156
57	159
58	164
59	172
60	176
61	177
62	180

n	a(n)
1	1
2	2
3	4
4	6
5	12
6	15
7	16
8	20
9	21
10	24
11	27
12	28
13	32
14	33
15	36
16	39
17	40
18	44
19	48
20	51
21	52
22	56
23	57
24	60
25	64
26	68
27	69
28	72
29	76
30	80
31	84
32	87
33	88
34	90
35	92
36	93
37	96
38	104
39	108
40	111
41	112
42	116
43	120
44	123
45	124
46	126
47	128
48	129
49	132
50	136
51	141
52	144
53	148
54	150
55	152
56	156
57	159
58	164
59	172
60	176
61	177
62	180

n	a(n)
1	1
2	2
3	4
4	6
5	12
6	15
7	16
8	20
9	21
10	24
11	27
12	28
13	32
14	33
15	36
16	39
17	40
18	44
19	48
20	51
21	52
22	56
23	57
24	60
25	64
26	68
27	69
28	72
29	76
30	80
31	84
32	87
33	88
34	90
35	92
36	93
37	96
38	104
39	108
40	111
41	112
42	116
43	120
44	123
45	124
46	126
47	128
48	129
49	132
50	136
51	141
52	144
53	148
54	150
55	152
56	156
57	159
58	164
59	172
60	176
61	177
62	180