A228780 - cp's OEIS frontend

A228780 Power basis components of the algebraic numbers S2(n) in Q(2*cos(Pi/n)), where S2(n) is the square of the sum of the lengths of the distinct line segments (side and diagonals) in the regular n-gon.

n	a(n)
2	4
3	3
4	6
5	4
6	3
7	4
8	12
9	6
10	-1
11	4
12	4
13	-2
14	-4
15	6
16	4
17	3
18	8
19	4
20	-16
21	-8
22	12
23	6
24	3
25	-4
26	-8
27	4
28	4
29	0
30	4
31	10
32	4
33	3
34	8
35	-8
36	-12
37	4
38	4
39	28
40	14
41	-40
42	-20
43	12
44	6
45	-1
46	8
47	12
48	4
49	-2
50	-8
51	28
52	28
53	-26
54	-20
55	6
56	4
57	-1
58	-8
59	16
60	28
61	-16
62	-20
63	4
64	4
65	4
66	2
67	-12
68	-6
69	8
70	4
71	3
72	-8
73	-24
74	28
75	44
76	-20
77	-24
78	4
79	4
80	0
81	8
82	28
83	-4
84	-40
85	-12
86	10
87	4
88	-1
89	-16
90	-24
91	0
92	12
93	4

[4, 3, 6, 4, 3, 4, 12, 6, -1, 4, 4, -2, -4, 6, 4, 3, 8, 4, -16, -8, 12, 6, 3, -4, -8, 4, 4, 0, 4, 10, 4, 3, 8, -8, -12, 4, 4, 28, 14, -40, -20, 12, 6, -1, 8, 12, 4, -2, -8, 28, 28, -26, -20, 6, 4, -1, -8, 16, 28, -16, -20, 4, 4, 4, 2, -12, -6, 8, 4, 3, -8, -24, 28, 44, -20, -24, 4, 4, 0, 8, 28, -4, -40, -12, 10, 4, -1, -16, -24, 0, 12, 4]

cp's OEIS Frontend

A228780 Power basis components of the algebraic numbers S2(n) in Q(2*cos(Pi/n)), where S2(n) is the square of the sum of the lengths of the distinct line segments (side and diagonals) in the regular n-gon.

Table of values

List of values

n	a(n)
2	4
3	3
4	6
5	4
6	3
7	4
8	12
9	6
10	-1
11	4
12	4
13	-2
14	-4
15	6
16	4
17	3
18	8
19	4
20	-16
21	-8
22	12
23	6
24	3
25	-4
26	-8
27	4
28	4
29	0
30	4
31	10
32	4
33	3
34	8
35	-8
36	-12
37	4
38	4
39	28
40	14
41	-40
42	-20
43	12
44	6
45	-1
46	8
47	12
48	4
49	-2
50	-8
51	28
52	28
53	-26
54	-20
55	6
56	4
57	-1
58	-8
59	16
60	28
61	-16
62	-20
63	4
64	4
65	4
66	2
67	-12
68	-6
69	8
70	4
71	3
72	-8
73	-24
74	28
75	44
76	-20
77	-24
78	4
79	4
80	0
81	8
82	28
83	-4
84	-40
85	-12
86	10
87	4
88	-1
89	-16
90	-24
91	0
92	12
93	4

n	a(n)
2	4
3	3
4	6
5	4
6	3
7	4
8	12
9	6
10	-1
11	4
12	4
13	-2
14	-4
15	6
16	4
17	3
18	8
19	4
20	-16
21	-8
22	12
23	6
24	3
25	-4
26	-8
27	4
28	4
29	0
30	4
31	10
32	4
33	3
34	8
35	-8
36	-12
37	4
38	4
39	28
40	14
41	-40
42	-20
43	12
44	6
45	-1
46	8
47	12
48	4
49	-2
50	-8
51	28
52	28
53	-26
54	-20
55	6
56	4
57	-1
58	-8
59	16
60	28
61	-16
62	-20
63	4
64	4
65	4
66	2
67	-12
68	-6
69	8
70	4
71	3
72	-8
73	-24
74	28
75	44
76	-20
77	-24
78	4
79	4
80	0
81	8
82	28
83	-4
84	-40
85	-12
86	10
87	4
88	-1
89	-16
90	-24
91	0
92	12
93	4

n	a(n)
2	4
3	3
4	6
5	4
6	3
7	4
8	12
9	6
10	-1
11	4
12	4
13	-2
14	-4
15	6
16	4
17	3
18	8
19	4
20	-16
21	-8
22	12
23	6
24	3
25	-4
26	-8
27	4
28	4
29	0
30	4
31	10
32	4
33	3
34	8
35	-8
36	-12
37	4
38	4
39	28
40	14
41	-40
42	-20
43	12
44	6
45	-1
46	8
47	12
48	4
49	-2
50	-8
51	28
52	28
53	-26
54	-20
55	6
56	4
57	-1
58	-8
59	16
60	28
61	-16
62	-20
63	4
64	4
65	4
66	2
67	-12
68	-6
69	8
70	4
71	3
72	-8
73	-24
74	28
75	44
76	-20
77	-24
78	4
79	4
80	0
81	8
82	28
83	-4
84	-40
85	-12
86	10
87	4
88	-1
89	-16
90	-24
91	0
92	12
93	4