A102248 - OEIS

A102248

Numbers n such that n111 is prime.

2, 4, 8, 10, 16, 22, 25, 26, 28, 35, 40, 44, 47, 50, 58, 65, 68, 70, 79, 80, 86, 92, 94, 95, 101, 109, 112, 113, 128, 131, 136, 140, 142, 143, 149, 152, 154, 169, 170, 179, 182, 184, 187, 196, 205, 208, 217, 218, 227, 235, 236, 260, 262, 263, 266, 278, 283, 284

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

At n=2, n111 = 2111 (prime).

At n=50, n111 = 50111 (prime).

At n=95, n111 = 95111 (prime).

MATHEMATICA

Select[ Range[ 290], PrimeQ[ FromDigits[ Flatten[ IntegerDigits /@ { #, 1, 1, 1}]]] &] (* Robert G. Wilson v, Feb 21 2005 *)

Select[Range[300], PrimeQ[1000#+111]&] (* Harvey P. Dale, Jul 07 2019 *)