A086227 - cp's OEIS frontend

A086227 a(n) = Sum_{1<=k<=4n, gcd(k,n)=1} (i^ktan(kPi/(4n)))/(4*i), where i is the imaginary unit.

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

[-1, 2, -2, 2, -4, 4, -4, 6, -4, 6, -8, 6, -8, 8, -8, 8, -12, 10, -8, 16, -12, 12, -16, 10, -12, 18, -16, 14, -16, 16, -16, 24, -16, 16, -24, 18, -20, 24, -16, 20, -32, 22, -24, 24, -24, 24, -32, 28, -20, 32, -24, 26, -36, 24, -32, 40, -28, 30, -32, 30, -32, 48, -32, 24, -48, 34, -32, 48, -32, 36, -48, 36, -36, 40, -40, 48, -48]

cp's OEIS Frontend

A086227 a(n) = Sum_{1<=k<=4n, gcd(k,n)=1} (i^ktan(kPi/(4n)))/(4*i), where i is the imaginary unit.

Table of values

List of values

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

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

cp's OEIS Frontend

A086227 a(n) = Sum_{1<=k<=4*n, gcd(k,n)=1} (i^k*tan(k*Pi/(4*n)))/(4*i), where i is the imaginary unit.

Table of values

List of values

A086227 a(n) = Sum_{1<=k<=4n, gcd(k,n)=1} (i^ktan(kPi/(4n)))/(4*i), where i is the imaginary unit.

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