A377899 - cp's OEIS frontend

A377899 a(n) = number of composite numbers c_{2*k+1} <= n, where c_m = A002808(m) is the m-th composite number.

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

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

cp's OEIS Frontend

A377899 a(n) = number of composite numbers c_{2*k+1} <= n, where c_m = A002808(m) is the m-th composite number.

Table of values

List of values

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

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

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