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Primes p such that 1*p + 8 and 8*p + 1 are primes.
0

%I #15 Sep 08 2022 08:45:17

%S 5,11,29,71,101,131,149,269,401,431,449,479,491,599,761,821,929,1229,

%T 1289,1559,1571,1601,1619,1871,2081,2129,2339,2531,2549,2609,2741,

%U 3041,3209,3299,3461,3719,3761,4289,5189,5861,6269,6359,6569,6701,6959,7211

%N Primes p such that 1*p + 8 and 8*p + 1 are primes.

%C Cf. A045536: Primes p such that 1*p+2 and 2*p+1 are prime; A007693: Numbers n such that n and 6*n+1 are primes.

%t Select[Prime[Range[220]], PrimeQ[8#+1]&&PrimeQ[1#+8]&]

%o (Magma) [p: p in PrimesUpTo(10000) | IsPrime(p+8) and IsPrime(8*p+1)]; // _Vincenzo Librandi_, Nov 13 2010

%Y Cf. A007693, A045536.

%K nonn

%O 1,1

%A _Zak Seidov_, May 07 2005