A125874 - cp's OEIS frontend

A125874 Numbers k such that p=22k+1 is prime and cos(2Pi/p) is an algebraic number of an 11-smooth degree, but not 7-smooth.

n	a(n)
1	1
2	3
3	4
4	9
5	15
6	16
7	18
8	21
9	28
10	30
11	33
12	40
13	45
14	60
15	64
16	66
17	81
18	96
19	99
20	105
21	108
22	121
23	135
24	144
25	150
26	154
27	165
28	168
29	175
30	189
31	198
32	210
33	225
34	240
35	243
36	250
37	288
38	294
39	324
40	336
41	343
42	378
43	396
44	420
45	448
46	450
47	490
48	495
49	525
50	528
51	550
52	616
53	625
54	640
55	675
56	700
57	726

[1, 3, 4, 9, 15, 16, 18, 21, 28, 30, 33, 40, 45, 60, 64, 66, 81, 96, 99, 105, 108, 121, 135, 144, 150, 154, 165, 168, 175, 189, 198, 210, 225, 240, 243, 250, 288, 294, 324, 336, 343, 378, 396, 420, 448, 450, 490, 495, 525, 528, 550, 616, 625, 640, 675, 700, 726]

cp's OEIS Frontend

A125874 Numbers k such that p=22k+1 is prime and cos(2Pi/p) is an algebraic number of an 11-smooth degree, but not 7-smooth.

Table of values

List of values

n	a(n)
1	1
2	3
3	4
4	9
5	15
6	16
7	18
8	21
9	28
10	30
11	33
12	40
13	45
14	60
15	64
16	66
17	81
18	96
19	99
20	105
21	108
22	121
23	135
24	144
25	150
26	154
27	165
28	168
29	175
30	189
31	198
32	210
33	225
34	240
35	243
36	250
37	288
38	294
39	324
40	336
41	343
42	378
43	396
44	420
45	448
46	450
47	490
48	495
49	525
50	528
51	550
52	616
53	625
54	640
55	675
56	700
57	726

n	a(n)
1	1
2	3
3	4
4	9
5	15
6	16
7	18
8	21
9	28
10	30
11	33
12	40
13	45
14	60
15	64
16	66
17	81
18	96
19	99
20	105
21	108
22	121
23	135
24	144
25	150
26	154
27	165
28	168
29	175
30	189
31	198
32	210
33	225
34	240
35	243
36	250
37	288
38	294
39	324
40	336
41	343
42	378
43	396
44	420
45	448
46	450
47	490
48	495
49	525
50	528
51	550
52	616
53	625
54	640
55	675
56	700
57	726

cp's OEIS Frontend

A125874 Numbers k such that p=22*k+1 is prime and cos(2*Pi/p) is an algebraic number of an 11-smooth degree, but not 7-smooth.

Table of values

List of values

A125874 Numbers k such that p=22k+1 is prime and cos(2Pi/p) is an algebraic number of an 11-smooth degree, but not 7-smooth.

n	a(n)
1	1
2	3
3	4
4	9
5	15
6	16
7	18
8	21
9	28
10	30
11	33
12	40
13	45
14	60
15	64
16	66
17	81
18	96
19	99
20	105
21	108
22	121
23	135
24	144
25	150
26	154
27	165
28	168
29	175
30	189
31	198
32	210
33	225
34	240
35	243
36	250
37	288
38	294
39	324
40	336
41	343
42	378
43	396
44	420
45	448
46	450
47	490
48	495
49	525
50	528
51	550
52	616
53	625
54	640
55	675
56	700
57	726