A085122 - cp's OEIS frontend

A085122 a(n) = PrimePi(sigma(n)-phi(n)) - (PrimePi(sigma(n)) - PrimePi(phi(n))), where PrimePi = A000720, sigma = A000203 and phi = A000010.

n	a(n)
1	0
2	-1
3	0
4	0
5	0
6	0
7	0
8	1
9	1
10	1
11	0
12	2
13	0
14	1
15	1
16	2
17	0
18	2
19	0
20	2
21	2
22	2
23	0
24	2
25	2
26	2
27	3
28	3
29	0
30	2
31	0
32	3
33	2
34	2
35	3
36	3
37	0
38	3
39	4
40	3
41	0
42	4
43	0
44	3
45	4
46	3
47	0
48	4
49	3
50	5
51	3
52	5
53	0
54	3
55	3
56	3
57	3
58	3
59	0
60	3
61	0
62	4
63	3
64	4
65	3
66	4
67	0
68	5
69	5
70	5
71	0
72	4
73	0
74	2
75	5
76	4
77	4
78	4
79	0
80	5
81	5
82	5
83	0
84	7
85	4
86	5
87	4
88	5
89	0
90	4
91	3
92	5
93	5
94	5
95	5
96	4
97	0
98	5
99	5
100	5
101	0
102	6
103	0
104	6
105	6
106	7
107	0
108	5
109	0
110	5
111	6
112	8
113	0
114	5
115	5
116	6
117	7
118	5
119	5
120	5
121	6
122	5
123	6
124	7
125	5
126	5
127	0
128	7

[0, -1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 2, 0, 1, 1, 2, 0, 2, 0, 2, 2, 2, 0, 2, 2, 2, 3, 3, 0, 2, 0, 3, 2, 2, 3, 3, 0, 3, 4, 3, 0, 4, 0, 3, 4, 3, 0, 4, 3, 5, 3, 5, 0, 3, 3, 3, 3, 3, 0, 3, 0, 4, 3, 4, 3, 4, 0, 5, 5, 5, 0, 4, 0, 2, 5, 4, 4, 4, 0, 5, 5, 5, 0, 7, 4, 5, 4, 5, 0, 4, 3, 5, 5, 5, 5, 4, 0, 5, 5, 5, 0, 6, 0, 6, 6, 7, 0, 5, 0, 5, 6, 8, 0, 5, 5, 6, 7, 5, 5, 5, 6, 5, 6, 7, 5, 5, 0, 7]

cp's OEIS Frontend

A085122 a(n) = PrimePi(sigma(n)-phi(n)) - (PrimePi(sigma(n)) - PrimePi(phi(n))), where PrimePi = A000720, sigma = A000203 and phi = A000010.

Table of values

List of values

n	a(n)
1	0
2	-1
3	0
4	0
5	0
6	0
7	0
8	1
9	1
10	1
11	0
12	2
13	0
14	1
15	1
16	2
17	0
18	2
19	0
20	2
21	2
22	2
23	0
24	2
25	2
26	2
27	3
28	3
29	0
30	2
31	0
32	3
33	2
34	2
35	3
36	3
37	0
38	3
39	4
40	3
41	0
42	4
43	0
44	3
45	4
46	3
47	0
48	4
49	3
50	5
51	3
52	5
53	0
54	3
55	3
56	3
57	3
58	3
59	0
60	3
61	0
62	4
63	3
64	4
65	3
66	4
67	0
68	5
69	5
70	5
71	0
72	4
73	0
74	2
75	5
76	4
77	4
78	4
79	0
80	5
81	5
82	5
83	0
84	7
85	4
86	5
87	4
88	5
89	0
90	4
91	3
92	5
93	5
94	5
95	5
96	4
97	0
98	5
99	5
100	5
101	0
102	6
103	0
104	6
105	6
106	7
107	0
108	5
109	0
110	5
111	6
112	8
113	0
114	5
115	5
116	6
117	7
118	5
119	5
120	5
121	6
122	5
123	6
124	7
125	5
126	5
127	0
128	7

n	a(n)
1	0
2	-1
3	0
4	0
5	0
6	0
7	0
8	1
9	1
10	1
11	0
12	2
13	0
14	1
15	1
16	2
17	0
18	2
19	0
20	2
21	2
22	2
23	0
24	2
25	2
26	2
27	3
28	3
29	0
30	2
31	0
32	3
33	2
34	2
35	3
36	3
37	0
38	3
39	4
40	3
41	0
42	4
43	0
44	3
45	4
46	3
47	0
48	4
49	3
50	5
51	3
52	5
53	0
54	3
55	3
56	3
57	3
58	3
59	0
60	3
61	0
62	4
63	3
64	4
65	3
66	4
67	0
68	5
69	5
70	5
71	0
72	4
73	0
74	2
75	5
76	4
77	4
78	4
79	0
80	5
81	5
82	5
83	0
84	7
85	4
86	5
87	4
88	5
89	0
90	4
91	3
92	5
93	5
94	5
95	5
96	4
97	0
98	5
99	5
100	5
101	0
102	6
103	0
104	6
105	6
106	7
107	0
108	5
109	0
110	5
111	6
112	8
113	0
114	5
115	5
116	6
117	7
118	5
119	5
120	5
121	6
122	5
123	6
124	7
125	5
126	5
127	0
128	7

n	a(n)
1	0
2	-1
3	0
4	0
5	0
6	0
7	0
8	1
9	1
10	1
11	0
12	2
13	0
14	1
15	1
16	2
17	0
18	2
19	0
20	2
21	2
22	2
23	0
24	2
25	2
26	2
27	3
28	3
29	0
30	2
31	0
32	3
33	2
34	2
35	3
36	3
37	0
38	3
39	4
40	3
41	0
42	4
43	0
44	3
45	4
46	3
47	0
48	4
49	3
50	5
51	3
52	5
53	0
54	3
55	3
56	3
57	3
58	3
59	0
60	3
61	0
62	4
63	3
64	4
65	3
66	4
67	0
68	5
69	5
70	5
71	0
72	4
73	0
74	2
75	5
76	4
77	4
78	4
79	0
80	5
81	5
82	5
83	0
84	7
85	4
86	5
87	4
88	5
89	0
90	4
91	3
92	5
93	5
94	5
95	5
96	4
97	0
98	5
99	5
100	5
101	0
102	6
103	0
104	6
105	6
106	7
107	0
108	5
109	0
110	5
111	6
112	8
113	0
114	5
115	5
116	6
117	7
118	5
119	5
120	5
121	6
122	5
123	6
124	7
125	5
126	5
127	0
128	7