A125867 - cp's OEIS frontend

A125867 Numbers k such that p=6k+1 is prime and cos(2*Pi/p) is an algebraic number of a 3-smooth degree, but not 2-smooth.

n	a(n)
1	1
2	2
3	3
4	6
5	12
6	16
7	18
8	27
9	32
10	72
11	81
12	96
13	128
14	192
15	216
16	243
17	432
18	486
19	576
20	648
21	1728
22	2048
23	2916
24	3072
25	6561
26	8748
27	23328
28	24576
29	34992
30	55296
31	78732
32	104976
33	124416
34	131072
35	139968
36	165888
37	196608
38	248832
39	294912
40	331776
41	442368
42	839808

[1, 2, 3, 6, 12, 16, 18, 27, 32, 72, 81, 96, 128, 192, 216, 243, 432, 486, 576, 648, 1728, 2048, 2916, 3072, 6561, 8748, 23328, 24576, 34992, 55296, 78732, 104976, 124416, 131072, 139968, 165888, 196608, 248832, 294912, 331776, 442368, 839808]

cp's OEIS Frontend

A125867 Numbers k such that p=6k+1 is prime and cos(2*Pi/p) is an algebraic number of a 3-smooth degree, but not 2-smooth.

Table of values

List of values