A074722 - cp's OEIS frontend

A074722 a(n) = Sum_{d divides n} phi(n/d)*(-1)^bigomega(d).

n	a(n)
1	1
2	0
3	1
4	2
5	3
6	0
7	5
8	2
9	5
10	0
11	9
12	2
13	11
14	0
15	3
16	6
17	15
18	0
19	17
20	6
21	5
22	0
23	21
24	2
25	17
26	0
27	13
28	10
29	27
30	0
31	29
32	10
33	9
34	0
35	15
36	10
37	35
38	0
39	11
40	6
41	39
42	0
43	41
44	18
45	15
46	0
47	45
48	6
49	37
50	0
51	15
52	22
53	51
54	0
55	27
56	10
57	17
58	0
59	57
60	6
61	59
62	0
63	25
64	22
65	33
66	0
67	65
68	30
69	21
70	0
71	69
72	10
73	71
74	0
75	17
76	34
77	45
78	0
79	77
80	18
81	41
82	0

[1, 0, 1, 2, 3, 0, 5, 2, 5, 0, 9, 2, 11, 0, 3, 6, 15, 0, 17, 6, 5, 0, 21, 2, 17, 0, 13, 10, 27, 0, 29, 10, 9, 0, 15, 10, 35, 0, 11, 6, 39, 0, 41, 18, 15, 0, 45, 6, 37, 0, 15, 22, 51, 0, 27, 10, 17, 0, 57, 6, 59, 0, 25, 22, 33, 0, 65, 30, 21, 0, 69, 10, 71, 0, 17, 34, 45, 0, 77, 18, 41, 0]

cp's OEIS Frontend

A074722 a(n) = Sum_{d divides n} phi(n/d)*(-1)^bigomega(d).

Table of values

List of values

n	a(n)
1	1
2	0
3	1
4	2
5	3
6	0
7	5
8	2
9	5
10	0
11	9
12	2
13	11
14	0
15	3
16	6
17	15
18	0
19	17
20	6
21	5
22	0
23	21
24	2
25	17
26	0
27	13
28	10
29	27
30	0
31	29
32	10
33	9
34	0
35	15
36	10
37	35
38	0
39	11
40	6
41	39
42	0
43	41
44	18
45	15
46	0
47	45
48	6
49	37
50	0
51	15
52	22
53	51
54	0
55	27
56	10
57	17
58	0
59	57
60	6
61	59
62	0
63	25
64	22
65	33
66	0
67	65
68	30
69	21
70	0
71	69
72	10
73	71
74	0
75	17
76	34
77	45
78	0
79	77
80	18
81	41
82	0

n	a(n)
1	1
2	0
3	1
4	2
5	3
6	0
7	5
8	2
9	5
10	0
11	9
12	2
13	11
14	0
15	3
16	6
17	15
18	0
19	17
20	6
21	5
22	0
23	21
24	2
25	17
26	0
27	13
28	10
29	27
30	0
31	29
32	10
33	9
34	0
35	15
36	10
37	35
38	0
39	11
40	6
41	39
42	0
43	41
44	18
45	15
46	0
47	45
48	6
49	37
50	0
51	15
52	22
53	51
54	0
55	27
56	10
57	17
58	0
59	57
60	6
61	59
62	0
63	25
64	22
65	33
66	0
67	65
68	30
69	21
70	0
71	69
72	10
73	71
74	0
75	17
76	34
77	45
78	0
79	77
80	18
81	41
82	0

n	a(n)
1	1
2	0
3	1
4	2
5	3
6	0
7	5
8	2
9	5
10	0
11	9
12	2
13	11
14	0
15	3
16	6
17	15
18	0
19	17
20	6
21	5
22	0
23	21
24	2
25	17
26	0
27	13
28	10
29	27
30	0
31	29
32	10
33	9
34	0
35	15
36	10
37	35
38	0
39	11
40	6
41	39
42	0
43	41
44	18
45	15
46	0
47	45
48	6
49	37
50	0
51	15
52	22
53	51
54	0
55	27
56	10
57	17
58	0
59	57
60	6
61	59
62	0
63	25
64	22
65	33
66	0
67	65
68	30
69	21
70	0
71	69
72	10
73	71
74	0
75	17
76	34
77	45
78	0
79	77
80	18
81	41
82	0