A124739 - cp's OEIS frontend

A124739 a(n) = sum of those positive integers which are coprime to both n and n+1 and which are <= n.

n	a(n)
1	1
2	1
3	1
4	4
5	1
6	6
7	9
8	13
9	8
10	20
11	13
12	24
13	29
14	25
15	32
16	64
17	37
18	54
19	61
20	61
21	55
22	110
23	73
24	91
25	111
26	108
27	114
28	168
29	91
30	120
31	225
32	170
33	153
34	199
35	144
36	216
37	305
38	221
39	175
40	320
41	211
42	252
43	397
44	261
45	249
46	506
47	337
48	342
49	423
50	351
51	403
52	624
53	433
54	410
55	483
56	431
57	493
58	812
59	421
60	480

[1, 1, 1, 4, 1, 6, 9, 13, 8, 20, 13, 24, 29, 25, 32, 64, 37, 54, 61, 61, 55, 110, 73, 91, 111, 108, 114, 168, 91, 120, 225, 170, 153, 199, 144, 216, 305, 221, 175, 320, 211, 252, 397, 261, 249, 506, 337, 342, 423, 351, 403, 624, 433, 410, 483, 431, 493, 812, 421, 480]

cp's OEIS Frontend

A124739 a(n) = sum of those positive integers which are coprime to both n and n+1 and which are <= n.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	4
5	1
6	6
7	9
8	13
9	8
10	20
11	13
12	24
13	29
14	25
15	32
16	64
17	37
18	54
19	61
20	61
21	55
22	110
23	73
24	91
25	111
26	108
27	114
28	168
29	91
30	120
31	225
32	170
33	153
34	199
35	144
36	216
37	305
38	221
39	175
40	320
41	211
42	252
43	397
44	261
45	249
46	506
47	337
48	342
49	423
50	351
51	403
52	624
53	433
54	410
55	483
56	431
57	493
58	812
59	421
60	480

n	a(n)
1	1
2	1
3	1
4	4
5	1
6	6
7	9
8	13
9	8
10	20
11	13
12	24
13	29
14	25
15	32
16	64
17	37
18	54
19	61
20	61
21	55
22	110
23	73
24	91
25	111
26	108
27	114
28	168
29	91
30	120
31	225
32	170
33	153
34	199
35	144
36	216
37	305
38	221
39	175
40	320
41	211
42	252
43	397
44	261
45	249
46	506
47	337
48	342
49	423
50	351
51	403
52	624
53	433
54	410
55	483
56	431
57	493
58	812
59	421
60	480

n	a(n)
1	1
2	1
3	1
4	4
5	1
6	6
7	9
8	13
9	8
10	20
11	13
12	24
13	29
14	25
15	32
16	64
17	37
18	54
19	61
20	61
21	55
22	110
23	73
24	91
25	111
26	108
27	114
28	168
29	91
30	120
31	225
32	170
33	153
34	199
35	144
36	216
37	305
38	221
39	175
40	320
41	211
42	252
43	397
44	261
45	249
46	506
47	337
48	342
49	423
50	351
51	403
52	624
53	433
54	410
55	483
56	431
57	493
58	812
59	421
60	480