A023268 - OEIS

%I #22 Sep 08 2022 08:44:47

%S 11,13,43,47,67,83,89,103,109,193,197,251,281,293,383,397,449,461,601,

%T 617,641,733,757,823,839,853,887,937,967,1013,1069,1091,1447,1489,

%U 1733,1741,1789,1931,2111,2237,2239,2251,2339,2521,2539,2647,2671,2693,2797

%N Primes that remain prime through 2 iterations of function f(x) = 9x + 10.

%C Primes p such that 9*p+10 and 81*p+100 are also primes. - _Vincenzo Librandi_, Aug 04 2010

%H John Cerkan, <a href="/A023268/b023268.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Prime[Range[500]],And@@PrimeQ[Rest[NestList[9#+10&,#,2]]]&] (* _Harvey P. Dale_, Jul 13 2012 *)

%o (Magma) [n: n in [1..100000] | IsPrime(n) and IsPrime(9*n+10) and IsPrime(81*n+100)] // _Vincenzo Librandi_, Aug 04 2010

%K nonn

%O 1,1

%A _David W. Wilson_