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%I #14 Mar 16 2023 10:19:41
%S 3,7,31,73,79,97,313,331,349,379,397,541,571,709,739,757,769,937,967,
%T 3037,3061,3067,3121,3163,3187,3217,3229,3253,3313,3319,3361,3433,
%U 3457,3529,3547,3613,3631,3643,3673,3739,3769,3847,3889,5011,5023,5101,5107
%N Primes p such that (p reversed)+4 is also a prime.
%H Harvey P. Dale, <a href="/A166501/b166501.txt">Table of n, a(n) for n = 1..1000</a>
%F {p = A000040(i): A004087(i)+4 in A000040}. - _R. J. Mathar_, Oct 16 2009
%e 73 is in the sequence because 37+4=41 prime.
%e 331 is in the sequence because 133+4=137 prime.
%e 3457 is in the sequence because 7543+4=7547 prime.
%t Select[Prime[Range[700]],PrimeQ[FromDigits[Reverse[IntegerDigits[#]]]+ 4]&] (* _Harvey P. Dale_, May 21 2012 *)
%t Select[Prime[Range[700]],PrimeQ[IntegerReverse[#]+4]&] (* _Harvey P. Dale_, Mar 16 2023 *)
%o (Magma) [p: p in PrimesUpTo(6000) | IsPrime(q+4) where q is Seqint(Reverse(Intseq(p)))]; // _Vincenzo Librandi_, Sep 15 2013
%K nonn,base,less
%O 1,1
%A _Vincenzo Librandi_, Oct 15 2009
%E Keyword:base added, 3163 inserted, sequence extended by _R. J. Mathar_, Oct 16 2009
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