A241845 - cp's OEIS frontend

A241845 a(1)=1; for n >1 a(n) is the smallest prime divisor of the number obtained from concatenation of 1 and the first n-1 composites.

n	a(n)
1	1
2	2
3	2
4	2
5	37
6	2
7	2
8	2
9	5
10	2
11	2
12	2
13	27793
14	2
15	2
16	3
17	2
18	29
19	2
20	2
21	2
22	19
23	2
24	5
25	2
26	2
27	1468910121415161820212224252627283032333435363839
28	2
29	2
30	2
31	5
32	2
33	2
34	3
35	2
36	127
37	2
38	2
39	5
40	2
41	3
42	2
43	2
44	2
45	3
46	2
47	3
48	2
49	2

[1, 2, 2, 2, 37, 2, 2, 2, 5, 2, 2, 2, 27793, 2, 2, 3, 2, 29, 2, 2, 2, 19, 2, 5, 2, 2, 1468910121415161820212224252627283032333435363839, 2, 2, 2, 5, 2, 2, 3, 2, 127, 2, 2, 5, 2, 3, 2, 2, 2, 3, 2, 3, 2, 2]

cp's OEIS Frontend

A241845 a(1)=1; for n >1 a(n) is the smallest prime divisor of the number obtained from concatenation of 1 and the first n-1 composites.

Table of values

List of values