A211658 - cp's OEIS frontend

A211658 Nonprime numbers k such that value of sigma(k) is unique; sigma(k) = A000203(k) = sum of divisors of k.

n	a(n)
1	1
2	4
3	8
4	9
5	12
6	18
7	22
8	27
9	32
10	36
11	45
12	49
13	50
14	64
15	72
16	81
17	91
18	98
19	100
20	106
21	121
22	128
23	129
24	133
25	134
26	146
27	148
28	152
29	162
30	169
31	171
32	192
33	200
34	202
35	217
36	218
37	219
38	243
39	256
40	259
41	262
42	268
43	274
44	288
45	289
46	292
47	301
48	314
49	324
50	333
51	338
52	343
53	361
54	381
55	386
56	388

[1, 4, 8, 9, 12, 18, 22, 27, 32, 36, 45, 49, 50, 64, 72, 81, 91, 98, 100, 106, 121, 128, 129, 133, 134, 146, 148, 152, 162, 169, 171, 192, 200, 202, 217, 218, 219, 243, 256, 259, 262, 268, 274, 288, 289, 292, 301, 314, 324, 333, 338, 343, 361, 381, 386, 388]

cp's OEIS Frontend

A211658 Nonprime numbers k such that 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	4
3	8
4	9
5	12
6	18
7	22
8	27
9	32
10	36
11	45
12	49
13	50
14	64
15	72
16	81
17	91
18	98
19	100
20	106
21	121
22	128
23	129
24	133
25	134
26	146
27	148
28	152
29	162
30	169
31	171
32	192
33	200
34	202
35	217
36	218
37	219
38	243
39	256
40	259
41	262
42	268
43	274
44	288
45	289
46	292
47	301
48	314
49	324
50	333
51	338
52	343
53	361
54	381
55	386
56	388

n	a(n)
1	1
2	4
3	8
4	9
5	12
6	18
7	22
8	27
9	32
10	36
11	45
12	49
13	50
14	64
15	72
16	81
17	91
18	98
19	100
20	106
21	121
22	128
23	129
24	133
25	134
26	146
27	148
28	152
29	162
30	169
31	171
32	192
33	200
34	202
35	217
36	218
37	219
38	243
39	256
40	259
41	262
42	268
43	274
44	288
45	289
46	292
47	301
48	314
49	324
50	333
51	338
52	343
53	361
54	381
55	386
56	388

n	a(n)
1	1
2	4
3	8
4	9
5	12
6	18
7	22
8	27
9	32
10	36
11	45
12	49
13	50
14	64
15	72
16	81
17	91
18	98
19	100
20	106
21	121
22	128
23	129
24	133
25	134
26	146
27	148
28	152
29	162
30	169
31	171
32	192
33	200
34	202
35	217
36	218
37	219
38	243
39	256
40	259
41	262
42	268
43	274
44	288
45	289
46	292
47	301
48	314
49	324
50	333
51	338
52	343
53	361
54	381
55	386
56	388