%I #17 Sep 08 2022 08:45:17

%S 3,7,13,19,31,43,97,103,157,181,241,271,337,349,409,421,439,547,631,

%T 691,733,811,829,937,1009,1021,1039,1249,1279,1291,1483,1489,1597,

%U 1609,1723,1867,2203,2287,2383,2437,2467,2539,2689,2719,2887,2953,3001,3109,3319

%N Primes p such that 1*p + 10 and 10*p + 1 are primes.

%H Harvey P. Dale, <a href="/A106061/b106061.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime[Range[220]], PrimeQ[10#+1]&&PrimeQ[1#+10]&]

%t Select[Prime[Range[500]],AllTrue[{10#+1,#+10},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Jun 15 2017 *)

%o (Magma) [p: p in PrimesUpTo(100000)| IsPrime(p+10) and IsPrime(10*p+1)]; // _Vincenzo Librandi_, Nov 13 2010

%Y Cf. A023203.

%K nonn

%O 1,1

%A _Zak Seidov_, May 07 2005