A097454 - cp's OEIS frontend

A097454 a(n) = (number of nonprimes <= n) - (number of primes <= n).

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

[1, 0, -1, 0, -1, 0, -1, 0, 1, 2, 1, 2, 1, 2, 3, 4, 3, 4, 3, 4, 5, 6, 5, 6, 7, 8, 9, 10, 9, 10, 9, 10, 11, 12, 13, 14, 13, 14, 15, 16, 15, 16, 15, 16, 17, 18, 17, 18, 19, 20, 21, 22, 21, 22, 23, 24, 25, 26, 25, 26, 25, 26, 27, 28, 29, 30, 29, 30, 31, 32, 31, 32, 31, 32, 33, 34, 35, 36, 35, 36, 37, 38, 37, 38, 39, 40, 41, 42, 41, 42, 43, 44, 45]

cp's OEIS Frontend

A097454 a(n) = (number of nonprimes <= n) - (number of primes <= n).

Table of values

List of values

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

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

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