A254886 - cp's OEIS frontend

A254886 a(n) = least k>0 such that n-k^2 and n+k^2 are both primes.

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	1
7	2
8	0
9	2
10	0
11	0
12	1
13	0
14	3
15	2
16	0
17	0
18	1
19	0
20	3
21	4
22	3
23	0
24	0
25	0
26	0
27	2
28	3
29	0
30	1
31	0
32	3
33	2
34	0
35	0
36	5
37	0
38	3
39	0
40	0
41	0
42	1
43	6
44	0
45	4
46	0
47	6
48	5
49	0
50	3
51	0
52	3
53	6
54	5
55	0
56	0
57	2
58	0
59	0
60	1
61	0
62	3
63	2
64	0
65	6
66	0
67	6
68	0
69	0
70	3
71	0
72	1
73	6
74	0
75	2
76	0
77	6
78	5
79	0
80	3
81	0
82	0
83	0
84	5
85	0
86	9
87	4
88	3
89	0
90	7
91	0
92	3
93	2
94	0
95	6
96	0
97	0
98	3
99	0
100	9
101	0
102	1
103	6
104	0
105	2
106	0
107	0
108	1
109	0

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

cp's OEIS Frontend

A254886 a(n) = least k>0 such that n-k^2 and n+k^2 are both primes.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	1
7	2
8	0
9	2
10	0
11	0
12	1
13	0
14	3
15	2
16	0
17	0
18	1
19	0
20	3
21	4
22	3
23	0
24	0
25	0
26	0
27	2
28	3
29	0
30	1
31	0
32	3
33	2
34	0
35	0
36	5
37	0
38	3
39	0
40	0
41	0
42	1
43	6
44	0
45	4
46	0
47	6
48	5
49	0
50	3
51	0
52	3
53	6
54	5
55	0
56	0
57	2
58	0
59	0
60	1
61	0
62	3
63	2
64	0
65	6
66	0
67	6
68	0
69	0
70	3
71	0
72	1
73	6
74	0
75	2
76	0
77	6
78	5
79	0
80	3
81	0
82	0
83	0
84	5
85	0
86	9
87	4
88	3
89	0
90	7
91	0
92	3
93	2
94	0
95	6
96	0
97	0
98	3
99	0
100	9
101	0
102	1
103	6
104	0
105	2
106	0
107	0
108	1
109	0

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	1
7	2
8	0
9	2
10	0
11	0
12	1
13	0
14	3
15	2
16	0
17	0
18	1
19	0
20	3
21	4
22	3
23	0
24	0
25	0
26	0
27	2
28	3
29	0
30	1
31	0
32	3
33	2
34	0
35	0
36	5
37	0
38	3
39	0
40	0
41	0
42	1
43	6
44	0
45	4
46	0
47	6
48	5
49	0
50	3
51	0
52	3
53	6
54	5
55	0
56	0
57	2
58	0
59	0
60	1
61	0
62	3
63	2
64	0
65	6
66	0
67	6
68	0
69	0
70	3
71	0
72	1
73	6
74	0
75	2
76	0
77	6
78	5
79	0
80	3
81	0
82	0
83	0
84	5
85	0
86	9
87	4
88	3
89	0
90	7
91	0
92	3
93	2
94	0
95	6
96	0
97	0
98	3
99	0
100	9
101	0
102	1
103	6
104	0
105	2
106	0
107	0
108	1
109	0

n	a(n)
1	0
2	0
3	0
4	1
5	0
6	1
7	2
8	0
9	2
10	0
11	0
12	1
13	0
14	3
15	2
16	0
17	0
18	1
19	0
20	3
21	4
22	3
23	0
24	0
25	0
26	0
27	2
28	3
29	0
30	1
31	0
32	3
33	2
34	0
35	0
36	5
37	0
38	3
39	0
40	0
41	0
42	1
43	6
44	0
45	4
46	0
47	6
48	5
49	0
50	3
51	0
52	3
53	6
54	5
55	0
56	0
57	2
58	0
59	0
60	1
61	0
62	3
63	2
64	0
65	6
66	0
67	6
68	0
69	0
70	3
71	0
72	1
73	6
74	0
75	2
76	0
77	6
78	5
79	0
80	3
81	0
82	0
83	0
84	5
85	0
86	9
87	4
88	3
89	0
90	7
91	0
92	3
93	2
94	0
95	6
96	0
97	0
98	3
99	0
100	9
101	0
102	1
103	6
104	0
105	2
106	0
107	0
108	1
109	0