A070555 - cp's OEIS frontend

A070555 Sum of positive integers k, where k <= n and gcd(k,2n+1) = gcd(k+1,2n+1).

n	a(n)
1	1
2	1
3	6
4	15
5	12
6	45
7	66
8	21
9	120
10	153
11	50
12	231
13	180
14	117
15	378
16	435
17	144
18	255
19	630
20	209
21	780
22	861
23	198
24	1035
25	840
26	375
27	1326
28	729
29	476
30	1653
31	1770
32	465
33	1056
34	2145
35	714
36	2415
37	2556
38	555
39	1710
40	3003
41	1080
42	3321
43	1890
44	1161
45	3828
46	2475
47	1334
48	2397
49	4560
50	1323

[1, 1, 6, 15, 12, 45, 66, 21, 120, 153, 50, 231, 180, 117, 378, 435, 144, 255, 630, 209, 780, 861, 198, 1035, 840, 375, 1326, 729, 476, 1653, 1770, 465, 1056, 2145, 714, 2415, 2556, 555, 1710, 3003, 1080, 3321, 1890, 1161, 3828, 2475, 1334, 2397, 4560, 1323]

cp's OEIS Frontend

A070555 Sum of positive integers k, where k <= n and gcd(k,2n+1) = gcd(k+1,2n+1).

Table of values

List of values