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A102248
Numbers n such that n111 is prime.
5
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
1,1
LINKS
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 *)
PROG
(PARI) is(n)=isprime(1000*n+111) \\ Charles R Greathouse IV, May 22 2017
CROSSREFS
Cf. A024912.
Sequence in context: A356232 A025612 A335239 * A161374 A272062 A045795
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Feb 18 2005
EXTENSIONS
More terms from Robert G. Wilson v, Feb 21 2005
STATUS
approved