A158819 - cp's OEIS frontend

A158819 a(n) = (number of squarefree numbers <= n) minus round(n/zeta(2)).

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

[0, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 2, 2, 2, 2, 1, 2, 1, 1, 2, 2, 2, 2, 1, 1, 0, 1, 1, 1, 1, 1]

cp's OEIS Frontend

A158819 a(n) = (number of squarefree numbers <= n) minus round(n/zeta(2)).

Table of values

List of values

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

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

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