A211781 - cp's OEIS frontend

A211781 Numbers n such that Sum_(d_ n) tau(d_ is an integer, where d_ divisors of n that are less than n, tau(x) = A000005(x).

n	a(n)
1	2
2	3
3	4
4	5
5	7
6	11
7	13
8	17
9	19
10	23
11	27
12	29
13	31
14	37
15	41
16	43
17	47
18	53
19	59
20	61
21	67
22	71
23	73
24	79
25	83
26	89
27	97
28	101
29	103
30	107
31	109
32	113
33	127
34	131
35	137
36	139
37	149
38	151
39	157
40	163
41	167
42	173
43	179
44	181
45	191
46	193
47	197
48	199
49	211
50	223
51	225
52	227
53	229
54	233
55	239
56	241
57	251
58	252

[2, 3, 4, 5, 7, 11, 13, 17, 19, 23, 27, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 225, 227, 229, 233, 239, 241, 251, 252]

cp's OEIS Frontend

A211781 Numbers n such that Sum_(d_ n) tau(d_ is an integer, where d_ divisors of n that are less than n, tau(x) = A000005(x).

Table of values

List of values

n	a(n)
1	2
2	3
3	4
4	5
5	7
6	11
7	13
8	17
9	19
10	23
11	27
12	29
13	31
14	37
15	41
16	43
17	47
18	53
19	59
20	61
21	67
22	71
23	73
24	79
25	83
26	89
27	97
28	101
29	103
30	107
31	109
32	113
33	127
34	131
35	137
36	139
37	149
38	151
39	157
40	163
41	167
42	173
43	179
44	181
45	191
46	193
47	197
48	199
49	211
50	223
51	225
52	227
53	229
54	233
55	239
56	241
57	251
58	252

n	a(n)
1	2
2	3
3	4
4	5
5	7
6	11
7	13
8	17
9	19
10	23
11	27
12	29
13	31
14	37
15	41
16	43
17	47
18	53
19	59
20	61
21	67
22	71
23	73
24	79
25	83
26	89
27	97
28	101
29	103
30	107
31	109
32	113
33	127
34	131
35	137
36	139
37	149
38	151
39	157
40	163
41	167
42	173
43	179
44	181
45	191
46	193
47	197
48	199
49	211
50	223
51	225
52	227
53	229
54	233
55	239
56	241
57	251
58	252

n	a(n)
1	2
2	3
3	4
4	5
5	7
6	11
7	13
8	17
9	19
10	23
11	27
12	29
13	31
14	37
15	41
16	43
17	47
18	53
19	59
20	61
21	67
22	71
23	73
24	79
25	83
26	89
27	97
28	101
29	103
30	107
31	109
32	113
33	127
34	131
35	137
36	139
37	149
38	151
39	157
40	163
41	167
42	173
43	179
44	181
45	191
46	193
47	197
48	199
49	211
50	223
51	225
52	227
53	229
54	233
55	239
56	241
57	251
58	252