A125871 - cp's OEIS frontend

A125871 Numbers k such that p=14k+1 is prime and cos(2Pi/p) is an algebraic number of a 7-smooth degree, but not 5-smooth.

n	a(n)
1	2
2	3
3	5
4	8
5	9
6	14
7	15
8	20
9	24
10	27
11	30
12	32
13	35
14	45
15	48
16	50
17	54
18	63
19	72
20	75
21	98
22	105
23	144
24	162
25	180
26	189
27	192
28	200
29	224
30	240
31	252
32	300
33	320
34	420
35	450
36	500
37	504
38	525
39	540
40	560
41	588
42	630
43	750
44	768
45	864
46	875
47	900
48	960
49	980
50	1029
51	1080
52	1134
53	1215
54	1280
55	1323

[2, 3, 5, 8, 9, 14, 15, 20, 24, 27, 30, 32, 35, 45, 48, 50, 54, 63, 72, 75, 98, 105, 144, 162, 180, 189, 192, 200, 224, 240, 252, 300, 320, 420, 450, 500, 504, 525, 540, 560, 588, 630, 750, 768, 864, 875, 900, 960, 980, 1029, 1080, 1134, 1215, 1280, 1323]

cp's OEIS Frontend

A125871 Numbers k such that p=14k+1 is prime and cos(2Pi/p) is an algebraic number of a 7-smooth degree, but not 5-smooth.

Table of values

List of values

cp's OEIS Frontend

A125871 Numbers k such that p=14*k+1 is prime and cos(2*Pi/p) is an algebraic number of a 7-smooth degree, but not 5-smooth.

Table of values

List of values

A125871 Numbers k such that p=14k+1 is prime and cos(2Pi/p) is an algebraic number of a 7-smooth degree, but not 5-smooth.