A072530 - cp's OEIS frontend

A072530 Number of primes p < n such that n divided by p leaves a prime remainder.

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

[0, 0, 0, 0, 1, 0, 1, 2, 1, 1, 1, 2, 2, 2, 1, 3, 3, 3, 2, 3, 1, 3, 3, 5, 2, 4, 2, 4, 3, 4, 3, 4, 4, 3, 2, 6, 4, 5, 2, 6, 4, 6, 3, 6, 4, 5, 5, 7, 4, 6, 4, 5, 4, 8, 3, 5, 4, 7, 5, 9, 3, 7, 5, 8, 5, 7, 3, 8, 4, 8, 5, 10, 6, 7, 5, 8, 4, 9, 6, 9, 7, 8, 4, 10, 5, 7, 6, 8, 7, 12, 5, 8, 8, 8, 5, 12, 6, 10, 5, 10, 5]

cp's OEIS Frontend

A072530 Number of primes p < n such that n divided by p leaves a prime remainder.

Table of values

List of values

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

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

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