A076608 - cp's OEIS frontend

A076608 Number of nonprimes k < n such that also n-k is not a prime.

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

[0, 1, 0, 0, 2, 0, 2, 1, 2, 4, 2, 3, 4, 4, 4, 7, 4, 7, 6, 7, 6, 10, 6, 11, 8, 12, 8, 13, 10, 15, 12, 13, 12, 18, 12, 21, 14, 16, 16, 21, 16, 23, 18, 21, 18, 24, 18, 27, 20, 27, 20, 27, 22, 31, 24, 29, 24, 32, 26, 37, 28, 30, 28, 37, 28, 41, 30, 33, 32, 41, 32, 43, 34, 40, 34, 43, 34]

cp's OEIS Frontend

A076608 Number of nonprimes k < n such that also n-k is not a prime.

Table of values

List of values

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

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

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