A304275 - cp's OEIS frontend

A304275 a(n) = Sum_{k = 1..n} gcd(k,n) / cos(Pi*k/n)^2 for odd n.

n	a(n)
1	1
2	11
3	29
4	55
5	105
6	131
7	181
8	319
9	305
10	379
11	605
12	551
13	745
14	963
15	869
16	991
17	1441
18	1595
19	1405
20	1991
21	1721
22	1891
23	3045
24	2255
25	2737
26	3355
27	2861
28	3799
29	4169
30	3539
31	3781
32	5775
33	5249
34	4555
35	6061
36	5111
37	5401
38	8195
39	7205
40	6319
41	8721
42	6971
43	8845

[1, 11, 29, 55, 105, 131, 181, 319, 305, 379, 605, 551, 745, 963, 869, 991, 1441, 1595, 1405, 1991, 1721, 1891, 3045, 2255, 2737, 3355, 2861, 3799, 4169, 3539, 3781, 5775, 5249, 4555, 6061, 5111, 5401, 8195, 7205, 6319, 8721, 6971, 8845]

cp's OEIS Frontend

A304275 a(n) = Sum_{k = 1..n} gcd(k,n) / cos(Pi*k/n)^2 for odd n.

Table of values

List of values