A233439 - cp's OEIS frontend

A233439 a(n) = |{0 < k < n: prime(k)^2 + 4*prime(n-k)^2 is prime}|.

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

[0, 0, 0, 1, 2, 1, 2, 1, 3, 4, 4, 8, 4, 6, 3, 1, 7, 3, 8, 5, 2, 9, 2, 11, 8, 7, 5, 4, 8, 7, 8, 8, 8, 7, 5, 9, 5, 10, 9, 7, 13, 9, 11, 10, 14, 5, 11, 10, 10, 11, 12, 7, 13, 10, 10, 8, 15, 11, 12, 11, 13, 14, 6, 12, 11, 22, 21, 5, 15, 7, 13, 15, 17, 15, 10, 16, 11, 13, 14, 12, 17, 12, 16, 16, 19, 22, 17, 12, 19, 17, 19, 17, 16, 17, 18, 20, 19, 17, 10, 16]

cp's OEIS Frontend

A233439 a(n) = |{0 < k < n: prime(k)^2 + 4*prime(n-k)^2 is prime}|.

Table of values

List of values

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

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

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