A372866 - cp's OEIS frontend

A372866 a(n) is the sum, over all positive integers x, y such that x*y <= n, of phi(gcd(x,y)).

n	a(n)
1	1
2	3
3	5
4	8
5	10
6	14
7	16
8	20
9	24
10	28
11	30
12	36
13	38
14	42
15	46
16	52
17	54
18	62
19	64
20	70
21	74
22	78
23	80
24	88
25	94
26	98
27	104
28	110
29	112
30	120
31	122
32	130
33	134
34	138
35	142
36	154
37	156
38	160
39	164
40	172
41	174
42	182
43	184
44	190
45	198
46	202
47	204
48	216
49	224
50	236
51	240
52	246
53	248
54	260
55	264
56	272
57	276
58	280

[1, 3, 5, 8, 10, 14, 16, 20, 24, 28, 30, 36, 38, 42, 46, 52, 54, 62, 64, 70, 74, 78, 80, 88, 94, 98, 104, 110, 112, 120, 122, 130, 134, 138, 142, 154, 156, 160, 164, 172, 174, 182, 184, 190, 198, 202, 204, 216, 224, 236, 240, 246, 248, 260, 264, 272, 276, 280]

cp's OEIS Frontend

A372866 a(n) is the sum, over all positive integers x, y such that x*y <= n, of phi(gcd(x,y)).

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	8
5	10
6	14
7	16
8	20
9	24
10	28
11	30
12	36
13	38
14	42
15	46
16	52
17	54
18	62
19	64
20	70
21	74
22	78
23	80
24	88
25	94
26	98
27	104
28	110
29	112
30	120
31	122
32	130
33	134
34	138
35	142
36	154
37	156
38	160
39	164
40	172
41	174
42	182
43	184
44	190
45	198
46	202
47	204
48	216
49	224
50	236
51	240
52	246
53	248
54	260
55	264
56	272
57	276
58	280

n	a(n)
1	1
2	3
3	5
4	8
5	10
6	14
7	16
8	20
9	24
10	28
11	30
12	36
13	38
14	42
15	46
16	52
17	54
18	62
19	64
20	70
21	74
22	78
23	80
24	88
25	94
26	98
27	104
28	110
29	112
30	120
31	122
32	130
33	134
34	138
35	142
36	154
37	156
38	160
39	164
40	172
41	174
42	182
43	184
44	190
45	198
46	202
47	204
48	216
49	224
50	236
51	240
52	246
53	248
54	260
55	264
56	272
57	276
58	280

n	a(n)
1	1
2	3
3	5
4	8
5	10
6	14
7	16
8	20
9	24
10	28
11	30
12	36
13	38
14	42
15	46
16	52
17	54
18	62
19	64
20	70
21	74
22	78
23	80
24	88
25	94
26	98
27	104
28	110
29	112
30	120
31	122
32	130
33	134
34	138
35	142
36	154
37	156
38	160
39	164
40	172
41	174
42	182
43	184
44	190
45	198
46	202
47	204
48	216
49	224
50	236
51	240
52	246
53	248
54	260
55	264
56	272
57	276
58	280