A231631 - cp's OEIS frontend

A231631 Least positive integer k < n with k!*(n-k) + 1 prime, or 0 if such an integer k does not exist.

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

[0, 1, 1, 2, 1, 3, 1, 2, 3, 2, 1, 4, 1, 3, 3, 2, 1, 4, 1, 2, 3, 2, 1, 3, 2, 3, 6, 2, 1, 3, 1, 2, 3, 6, 2, 3, 1, 2, 6, 3, 1, 5, 1, 6, 5, 2, 1, 3, 3, 2, 4, 2, 1, 3, 2, 2, 6, 2, 1, 11, 1, 5, 5, 3, 2, 3, 1, 5, 3, 2, 1, 6, 1, 7, 3, 2, 2, 4, 1, 2, 6, 4, 1, 3, 2, 3, 4, 2, 1, 3, 2, 2, 3, 3, 6, 7, 1, 2, 3, 2]

cp's OEIS Frontend

A231631 Least positive integer k < n with k!*(n-k) + 1 prime, or 0 if such an integer k does not exist.

Table of values

List of values

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

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

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