A111473 - cp's OEIS frontend

A111473 a(1) = 3, a(n) = least k such that concatenation of n copies of k with all previous concatenation gives a prime.

n	a(n)
1	3
2	1
3	1
4	11
5	113
6	7
7	23
8	41
9	37
10	141
11	733
12	241
13	3
14	791
15	781
16	701
17	239
18	441
19	2019
20	189
21	2071
22	401
23	851
24	463
25	4421
26	497
27	2267
28	213
29	1653
30	1683
31	1227
32	667
33	3261
34	6673
35	5799
36	3579
37	1907
38	6483
39	7813
40	2443
41	1923
42	11439
43	6657
44	7861
45	1847
46	7521
47	8277
48	8459

[3, 1, 1, 11, 113, 7, 23, 41, 37, 141, 733, 241, 3, 791, 781, 701, 239, 441, 2019, 189, 2071, 401, 851, 463, 4421, 497, 2267, 213, 1653, 1683, 1227, 667, 3261, 6673, 5799, 3579, 1907, 6483, 7813, 2443, 1923, 11439, 6657, 7861, 1847, 7521, 8277, 8459]

cp's OEIS Frontend

A111473 a(1) = 3, a(n) = least k such that concatenation of n copies of k with all previous concatenation gives a prime.

Table of values

List of values