A125868 - cp's OEIS frontend

A125868 Odd numbers k such that cos(2*Pi/k) is an algebraic number of a 5-smooth degree, but not 3-smooth.

n	a(n)
1	11
2	25
3	31
4	33
5	41
6	55
7	61
8	75
9	77
10	93
11	99
12	101
13	123
14	125
15	143
16	151
17	155
18	165
19	175
20	181
21	183
22	187
23	205
24	209
25	217
26	225
27	231
28	241
29	251
30	271
31	275
32	279
33	287
34	297
35	303
36	305
37	325
38	341
39	369
40	375
41	385
42	401
43	403
44	407
45	425
46	427
47	429
48	451
49	453
50	465
51	475
52	495
53	505
54	525

[11, 25, 31, 33, 41, 55, 61, 75, 77, 93, 99, 101, 123, 125, 143, 151, 155, 165, 175, 181, 183, 187, 205, 209, 217, 225, 231, 241, 251, 271, 275, 279, 287, 297, 303, 305, 325, 341, 369, 375, 385, 401, 403, 407, 425, 427, 429, 451, 453, 465, 475, 495, 505, 525]

cp's OEIS Frontend

A125868 Odd numbers k such that cos(2*Pi/k) is an algebraic number of a 5-smooth degree, but not 3-smooth.

Table of values

List of values

n	a(n)
1	11
2	25
3	31
4	33
5	41
6	55
7	61
8	75
9	77
10	93
11	99
12	101
13	123
14	125
15	143
16	151
17	155
18	165
19	175
20	181
21	183
22	187
23	205
24	209
25	217
26	225
27	231
28	241
29	251
30	271
31	275
32	279
33	287
34	297
35	303
36	305
37	325
38	341
39	369
40	375
41	385
42	401
43	403
44	407
45	425
46	427
47	429
48	451
49	453
50	465
51	475
52	495
53	505
54	525

n	a(n)
1	11
2	25
3	31
4	33
5	41
6	55
7	61
8	75
9	77
10	93
11	99
12	101
13	123
14	125
15	143
16	151
17	155
18	165
19	175
20	181
21	183
22	187
23	205
24	209
25	217
26	225
27	231
28	241
29	251
30	271
31	275
32	279
33	287
34	297
35	303
36	305
37	325
38	341
39	369
40	375
41	385
42	401
43	403
44	407
45	425
46	427
47	429
48	451
49	453
50	465
51	475
52	495
53	505
54	525

n	a(n)
1	11
2	25
3	31
4	33
5	41
6	55
7	61
8	75
9	77
10	93
11	99
12	101
13	123
14	125
15	143
16	151
17	155
18	165
19	175
20	181
21	183
22	187
23	205
24	209
25	217
26	225
27	231
28	241
29	251
30	271
31	275
32	279
33	287
34	297
35	303
36	305
37	325
38	341
39	369
40	375
41	385
42	401
43	403
44	407
45	425
46	427
47	429
48	451
49	453
50	465
51	475
52	495
53	505
54	525