A215421 - cp's OEIS frontend

A215421 Primes that remain prime when a single digit 9 is inserted between any two consecutive digits or as the leading or trailing digit.

n	a(n)
1	7
2	19
3	37
4	41
5	199
6	239
7	311
8	587
9	661
10	941
11	967
12	1009
13	1997
14	4993
15	4999
16	5393
17	5651
18	6911
19	9109
20	9397
21	9679
22	9829
23	19417
24	20233
25	22549
26	27397
27	29389
28	31387
29	39989
30	71419
31	71569
32	90599
33	91951
34	95369
35	97103
36	98909
37	99023
38	160009
39	225919
40	267389
41	313991
42	328849

[7, 19, 37, 41, 199, 239, 311, 587, 661, 941, 967, 1009, 1997, 4993, 4999, 5393, 5651, 6911, 9109, 9397, 9679, 9829, 19417, 20233, 22549, 27397, 29389, 31387, 39989, 71419, 71569, 90599, 91951, 95369, 97103, 98909, 99023, 160009, 225919, 267389, 313991, 328849]

cp's OEIS Frontend

A215421 Primes that remain prime when a single digit 9 is inserted between any two consecutive digits or as the leading or trailing digit.

Table of values

List of values