A376760 - cp's OEIS frontend

A376760 Let c(n) = A002808(n) denote the n-th composite number; a(n) = number of composite numbers c with c(n) <= c <= 2*c(n).

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

[3, 5, 7, 7, 7, 9, 12, 12, 12, 15, 17, 17, 17, 19, 20, 21, 21, 22, 24, 26, 27, 27, 28, 28, 30, 31, 31, 33, 36, 36, 37, 40, 40, 41, 41, 41, 43, 43, 44, 44, 45, 48, 51, 52, 52, 53, 53, 56, 56, 56, 59, 62, 62, 62, 63, 64, 66, 67, 67, 69, 70, 71, 71, 72, 74, 74, 75, 76, 77, 78, 78, 80, 80, 80, 83, 86, 87, 87, 90, 93, 94, 94, 96, 96, 97, 97, 98, 99, 99, 99, 100, 101, 102, 103]

cp's OEIS Frontend

A376760 Let c(n) = A002808(n) denote the n-th composite number; a(n) = number of composite numbers c with c(n) <= c <= 2*c(n).

Table of values

List of values

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

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

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