A331045 - cp's OEIS frontend

A331045 a(n) is the least prime number of the form floor(n/10^k) for some k >= 0, or 0 if no such prime number exists.

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

[0, 0, 2, 3, 0, 5, 0, 7, 0, 0, 0, 11, 0, 13, 0, 0, 0, 17, 0, 19, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 0, 41, 0, 43, 0, 0, 0, 47, 0, 0, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 0, 61, 0, 0, 0, 0, 0, 67, 0, 0, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 0, 0, 0, 83]

cp's OEIS Frontend

A331045 a(n) is the least prime number of the form floor(n/10^k) for some k >= 0, or 0 if no such prime number exists.

Table of values

List of values

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

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

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