A231883 - cp's OEIS frontend

A231883 Number of ways to write n = x + y (x, y > 0) with x^2 + (n-2)*y^2 prime.

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

[0, 0, 2, 2, 2, 2, 4, 1, 5, 2, 5, 1, 4, 4, 3, 1, 7, 2, 3, 3, 6, 7, 3, 2, 6, 2, 9, 3, 8, 3, 10, 3, 5, 8, 8, 4, 7, 5, 13, 4, 12, 6, 7, 6, 8, 10, 14, 4, 17, 9, 9, 6, 9, 5, 8, 5, 9, 7, 12, 10, 11, 7, 11, 8, 12, 4, 13, 3, 22, 6, 16, 7, 14, 8, 10, 4, 14, 4, 17, 9, 16, 6, 12, 11, 14, 4, 21, 4, 21, 8, 18, 3, 11, 14, 23, 7, 22, 5, 23, 8]

cp's OEIS Frontend

A231883 Number of ways to write n = x + y (x, y > 0) with x^2 + (n-2)*y^2 prime.

Table of values

List of values

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

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

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