A144740 - cp's OEIS frontend

A144740 Partial totient function phi(c, n) for c = 2: number of semiprimes less than and coprime to n.

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	2
8	0
9	1
10	1
11	4
12	0
13	4
14	1
15	2
16	2
17	6
18	0
19	6
20	1
21	2
22	3
23	8
24	0
25	6
26	4
27	6
28	3
29	10
30	0
31	10
32	4
33	5
34	5
35	7
36	2
37	13
38	6
39	8
40	4
41	15
42	1
43	15
44	6
45	6
46	7
47	16
48	2
49	13
50	5
51	10
52	8
53	18
54	3
55	12
56	7
57	11
58	11
59	21
60	1
61	21
62	11
63	11
64	11
65	15
66	4
67	23
68	11
69	14
70	6
71	24
72	5
73	24
74	13
75	11
76	12
77	18
78	5
79	26
80	9
81	17
82	14
83	27
84	3
85	19
86	15
87	19

[0, 0, 0, 0, 1, 0, 2, 0, 1, 1, 4, 0, 4, 1, 2, 2, 6, 0, 6, 1, 2, 3, 8, 0, 6, 4, 6, 3, 10, 0, 10, 4, 5, 5, 7, 2, 13, 6, 8, 4, 15, 1, 15, 6, 6, 7, 16, 2, 13, 5, 10, 8, 18, 3, 12, 7, 11, 11, 21, 1, 21, 11, 11, 11, 15, 4, 23, 11, 14, 6, 24, 5, 24, 13, 11, 12, 18, 5, 26, 9, 17, 14, 27, 3, 19, 15, 19]

cp's OEIS Frontend

A144740 Partial totient function phi(c, n) for c = 2: number of semiprimes less than and coprime to n.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	2
8	0
9	1
10	1
11	4
12	0
13	4
14	1
15	2
16	2
17	6
18	0
19	6
20	1
21	2
22	3
23	8
24	0
25	6
26	4
27	6
28	3
29	10
30	0
31	10
32	4
33	5
34	5
35	7
36	2
37	13
38	6
39	8
40	4
41	15
42	1
43	15
44	6
45	6
46	7
47	16
48	2
49	13
50	5
51	10
52	8
53	18
54	3
55	12
56	7
57	11
58	11
59	21
60	1
61	21
62	11
63	11
64	11
65	15
66	4
67	23
68	11
69	14
70	6
71	24
72	5
73	24
74	13
75	11
76	12
77	18
78	5
79	26
80	9
81	17
82	14
83	27
84	3
85	19
86	15
87	19

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	2
8	0
9	1
10	1
11	4
12	0
13	4
14	1
15	2
16	2
17	6
18	0
19	6
20	1
21	2
22	3
23	8
24	0
25	6
26	4
27	6
28	3
29	10
30	0
31	10
32	4
33	5
34	5
35	7
36	2
37	13
38	6
39	8
40	4
41	15
42	1
43	15
44	6
45	6
46	7
47	16
48	2
49	13
50	5
51	10
52	8
53	18
54	3
55	12
56	7
57	11
58	11
59	21
60	1
61	21
62	11
63	11
64	11
65	15
66	4
67	23
68	11
69	14
70	6
71	24
72	5
73	24
74	13
75	11
76	12
77	18
78	5
79	26
80	9
81	17
82	14
83	27
84	3
85	19
86	15
87	19

n	a(n)
1	0
2	0
3	0
4	0
5	1
6	0
7	2
8	0
9	1
10	1
11	4
12	0
13	4
14	1
15	2
16	2
17	6
18	0
19	6
20	1
21	2
22	3
23	8
24	0
25	6
26	4
27	6
28	3
29	10
30	0
31	10
32	4
33	5
34	5
35	7
36	2
37	13
38	6
39	8
40	4
41	15
42	1
43	15
44	6
45	6
46	7
47	16
48	2
49	13
50	5
51	10
52	8
53	18
54	3
55	12
56	7
57	11
58	11
59	21
60	1
61	21
62	11
63	11
64	11
65	15
66	4
67	23
68	11
69	14
70	6
71	24
72	5
73	24
74	13
75	11
76	12
77	18
78	5
79	26
80	9
81	17
82	14
83	27
84	3
85	19
86	15
87	19