A245727 - cp's OEIS frontend

A245727 Least number k >= 0 such that n concatenated with n + k is prime.

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

[0, 1, 4, 3, 4, 1, 2, 1, 2, 3, 6, 1, 6, 9, 8, 3, 4, 5, 12, 7, 8, 15, 10, 13, 6, 7, 2, 5, 10, 7, 6, 19, 10, 15, 4, 1, 2, 9, 4, 9, 12, 1, 6, 3, 2, 3, 4, 13, 2, 1, 2, 9, 28, 17, 2, 1, 22, 3, 22, 7, 2, 1, 4, 5, 4, 7, 12, 1, 2, 9, 6, 11, 20, 3, 2, 5, 12, 1, 14, 1, 10, 5, 4, 37, 12, 3, 16, 5, 10]

cp's OEIS Frontend

A245727 Least number k >= 0 such that n concatenated with n + k is prime.

Table of values

List of values

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

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

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