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

Offset: 1

Author

Parthasarathy Nambi, Feb 18 2005

Keywords

• nonn
• base

Examples

			At n=2, n111 = 2111 (prime).
At n=50, n111 = 50111 (prime).
At n=95, n111 = 95111 (prime).
		

Links

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

Crossrefs

Cf. A024912.

Programs

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 *)

PARI

is(n)=isprime(1000*n+111) \\ Charles R Greathouse IV, May 22 2017

Extensions

More terms from Robert G. Wilson v, Feb 21 2005