A306353 - cp's OEIS frontend

A306353 Number of composites among the first n composite numbers whose least prime factor p is that of the n-th composite number.

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

[1, 2, 3, 1, 4, 5, 6, 2, 7, 8, 9, 3, 10, 11, 1, 12, 4, 13, 14, 15, 5, 16, 2, 17, 18, 6, 19, 20, 21, 7, 22, 23, 1, 24, 8, 25, 26, 3, 27, 9, 28, 29, 30, 10, 31, 4, 32, 33, 11, 34, 35, 36, 12, 37, 2, 38, 39, 13, 40, 41, 5, 42, 14, 43, 44, 3, 45, 15, 46, 6, 47, 48, 16, 49, 50, 51, 17, 52, 53, 54, 18, 55, 56, 7]

cp's OEIS Frontend

A306353 Number of composites among the first n composite numbers whose least prime factor p is that of the n-th composite number.

Table of values

List of values

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

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

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