A235149 - OEIS

%I #10 May 20 2023 09:49:22

%S 43,61,67,229,241,271,283,409,421,439,457,601,643,661,673,2011,2017,

%T 2029,2113,2131,2161,2179,2221,2269,2287,2293,2341,2389,2437,2467,

%U 2521,2551,2557,2707,2749,2791,2803,2833,2857,4003,4027,4051,4093,4129,4159,4201,4339,4357

%N Primes p such that (p reversed) + 7 is also a prime.

%H Vincenzo Librandi, <a href="/A235149/b235149.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime[Range[6000]], PrimeQ[FromDigits[Reverse[IntegerDigits[#]]] + 7]&]

%t Select[Prime[Range[600]],PrimeQ[IntegerReverse[#]+7]&] (* _Harvey P. Dale_, May 20 2023 *)

%o (Magma) [p: p in PrimesUpTo(6000) | IsPrime(q+7) where q is Seqint(Reverse(Intseq(p)))];

%Y Cf. A165446, A166501, A167460, A167466, A167473.

%K nonn,base

%O 1,1

%A _Vincenzo Librandi_, Jan 04 2014