A383613 - cp's OEIS frontend

A383613 Square array read by antidiagonals upwards: T(n,k) (for n>1 and k>0) is the smallest k-digit prime p such that prevprime(p) appears as a substring in p^n; or -1 if no such prime exists.

n	a(n)
2	-1
3	3
4	-1
5	-1
6	17
7	-1
8	3
9	43
10	997
11	3701
12	3
13	31
14	607
15	2837
16	-1
17	3
18	11
19	929
20	5843
21	57349
22	-1
23	5
24	11
25	-1
26	4447
27	31063
28	224813
29	-1
30	5
31	-1
32	277
33	2477
34	77377
35	292223
36	9999991
37	65442077
38	7
39	11
40	809
41	7019
42	24379
43	262433
44	9862243
45	61879669
46	-1
47	-1
48	11
49	499
50	1571
51	17669
52	342281
53	1303613
54	32685743
55	763137931
56	-1

[-1, 3, -1, -1, 17, -1, 3, 43, 997, 3701, 3, 31, 607, 2837, -1, 3, 11, 929, 5843, 57349, -1, 5, 11, -1, 4447, 31063, 224813, -1, 5, -1, 277, 2477, 77377, 292223, 9999991, 65442077, 7, 11, 809, 7019, 24379, 262433, 9862243, 61879669, -1, -1, 11, 499, 1571, 17669, 342281, 1303613, 32685743, 763137931, -1]

cp's OEIS Frontend

A383613 Square array read by antidiagonals upwards: T(n,k) (for n>1 and k>0) is the smallest k-digit prime p such that prevprime(p) appears as a substring in p^n; or -1 if no such prime exists.

Table of values

List of values