A241020 - cp's OEIS frontend

A241020 a(n) is the smallest j such that the n-digit number consisting of a 1 in position j and 7's in the other n-1 positions is a prime, or 0 if no such prime exists.

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

[1, 0, 1, 2, 0, 0, 6, 0, 1, 2, 0, 2, 1, 0, 3, 0, 0, 5, 2, 0, 6, 4, 0, 7, 4, 0, 12, 0, 0, 19, 8, 0, 26, 5, 0, 0, 33, 0, 6, 11, 0, 1, 23, 0, 18, 34, 0, 15, 0, 0, 1, 22, 0, 1, 50, 0, 32, 15, 0, 15, 25, 0, 21, 10, 0, 29, 47, 0, 0, 11, 0, 56, 14, 0, 2, 0, 0, 54, 3]

cp's OEIS Frontend

A241020 a(n) is the smallest j such that the n-digit number consisting of a 1 in position j and 7's in the other n-1 positions is a prime, or 0 if no such prime exists.

Table of values

List of values

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

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

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