A211656 - cp's OEIS frontend

A211656 Numbers k such that the value of sigma(k) is unique; sigma(k) = A000203(k) = sum of divisors of k.

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	7
7	8
8	9
9	12
10	13
11	18
12	19
13	22
14	27
15	29
16	32
17	36
18	37
19	43
20	45
21	49
22	50
23	61
24	64
25	67
26	72
27	73
28	81
29	91
30	98
31	100
32	101
33	106
34	109
35	121
36	128
37	129
38	133
39	134
40	137
41	146
42	148
43	149
44	152
45	157
46	162
47	163
48	169
49	171
50	173
51	192
52	193
53	197
54	199
55	200
56	202
57	211
58	217
59	218
60	219

[1, 2, 3, 4, 5, 7, 8, 9, 12, 13, 18, 19, 22, 27, 29, 32, 36, 37, 43, 45, 49, 50, 61, 64, 67, 72, 73, 81, 91, 98, 100, 101, 106, 109, 121, 128, 129, 133, 134, 137, 146, 148, 149, 152, 157, 162, 163, 169, 171, 173, 192, 193, 197, 199, 200, 202, 211, 217, 218, 219]

cp's OEIS Frontend

A211656 Numbers k such that the value of sigma(k) is unique; sigma(k) = A000203(k) = sum of divisors of k.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	7
7	8
8	9
9	12
10	13
11	18
12	19
13	22
14	27
15	29
16	32
17	36
18	37
19	43
20	45
21	49
22	50
23	61
24	64
25	67
26	72
27	73
28	81
29	91
30	98
31	100
32	101
33	106
34	109
35	121
36	128
37	129
38	133
39	134
40	137
41	146
42	148
43	149
44	152
45	157
46	162
47	163
48	169
49	171
50	173
51	192
52	193
53	197
54	199
55	200
56	202
57	211
58	217
59	218
60	219

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	7
7	8
8	9
9	12
10	13
11	18
12	19
13	22
14	27
15	29
16	32
17	36
18	37
19	43
20	45
21	49
22	50
23	61
24	64
25	67
26	72
27	73
28	81
29	91
30	98
31	100
32	101
33	106
34	109
35	121
36	128
37	129
38	133
39	134
40	137
41	146
42	148
43	149
44	152
45	157
46	162
47	163
48	169
49	171
50	173
51	192
52	193
53	197
54	199
55	200
56	202
57	211
58	217
59	218
60	219

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	7
7	8
8	9
9	12
10	13
11	18
12	19
13	22
14	27
15	29
16	32
17	36
18	37
19	43
20	45
21	49
22	50
23	61
24	64
25	67
26	72
27	73
28	81
29	91
30	98
31	100
32	101
33	106
34	109
35	121
36	128
37	129
38	133
39	134
40	137
41	146
42	148
43	149
44	152
45	157
46	162
47	163
48	169
49	171
50	173
51	192
52	193
53	197
54	199
55	200
56	202
57	211
58	217
59	218
60	219