A069823 - cp's OEIS frontend

A069823 Nonprime numbers k for which there is no x < k such that phi(x) = phi(k).

n	a(n)
1	1
2	15
3	25
4	35
5	51
6	65
7	69
8	81
9	85
10	87
11	121
12	123
13	129
14	141
15	143
16	159
17	161
18	177
19	185
20	187
21	203
22	213
23	235
24	247
25	249
26	253
27	255
28	265
29	267
30	275
31	289
32	299
33	301
34	309
35	321
36	323
37	339
38	341
39	343
40	361
41	393
42	403
43	415
44	425
45	447
46	485
47	489
48	501
49	519
50	527
51	529
52	535
53	537
54	551

[1, 15, 25, 35, 51, 65, 69, 81, 85, 87, 121, 123, 129, 141, 143, 159, 161, 177, 185, 187, 203, 213, 235, 247, 249, 253, 255, 265, 267, 275, 289, 299, 301, 309, 321, 323, 339, 341, 343, 361, 393, 403, 415, 425, 447, 485, 489, 501, 519, 527, 529, 535, 537, 551]

cp's OEIS Frontend

A069823 Nonprime numbers k for which there is no x < k such that phi(x) = phi(k).

Table of values

List of values

n	a(n)
1	1
2	15
3	25
4	35
5	51
6	65
7	69
8	81
9	85
10	87
11	121
12	123
13	129
14	141
15	143
16	159
17	161
18	177
19	185
20	187
21	203
22	213
23	235
24	247
25	249
26	253
27	255
28	265
29	267
30	275
31	289
32	299
33	301
34	309
35	321
36	323
37	339
38	341
39	343
40	361
41	393
42	403
43	415
44	425
45	447
46	485
47	489
48	501
49	519
50	527
51	529
52	535
53	537
54	551

n	a(n)
1	1
2	15
3	25
4	35
5	51
6	65
7	69
8	81
9	85
10	87
11	121
12	123
13	129
14	141
15	143
16	159
17	161
18	177
19	185
20	187
21	203
22	213
23	235
24	247
25	249
26	253
27	255
28	265
29	267
30	275
31	289
32	299
33	301
34	309
35	321
36	323
37	339
38	341
39	343
40	361
41	393
42	403
43	415
44	425
45	447
46	485
47	489
48	501
49	519
50	527
51	529
52	535
53	537
54	551

n	a(n)
1	1
2	15
3	25
4	35
5	51
6	65
7	69
8	81
9	85
10	87
11	121
12	123
13	129
14	141
15	143
16	159
17	161
18	177
19	185
20	187
21	203
22	213
23	235
24	247
25	249
26	253
27	255
28	265
29	267
30	275
31	289
32	299
33	301
34	309
35	321
36	323
37	339
38	341
39	343
40	361
41	393
42	403
43	415
44	425
45	447
46	485
47	489
48	501
49	519
50	527
51	529
52	535
53	537
54	551