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%I #6 Dec 15 2021 18:40:29
%S 7,43,47,67,149,163,167,337,353,487,587,617,787,911,947,1367,1777,
%T 1783,2333,2347,2503,2927,2953,2963,3023,3607,3613,3637,3643,3697,
%U 3709,3847,4363,4397,4423,4463,4483,4903,5273,6113,6143,6197,7103,7187,7193,8117
%N Primes p such that p-+(floor(Sqrt(p)))^2 are primes.
%H Harvey P. Dale, <a href="/A173828/b173828.txt">Table of n, a(n) for n = 1..1000</a>
%t f1[n_]:=n-(Floor[Sqrt[n]])^2;f2[n_]:=n+(Floor[Sqrt[n]])^2;lst={};Do[p=Prime[n];If[PrimeQ[f1[p]]&&PrimeQ[f2[p]],AppendTo[lst,p]],{n,8!}];lst
%t fQ[n_]:=Module[{c=Floor[Sqrt[n]]^2},AllTrue[n+{c,-c},PrimeQ]]; Select[ Prime[ Range[1200]],fQ] (* _Harvey P. Dale_, Dec 15 2021 *)
%Y Cf. A086085, A086086, A135932, A173826, A173827
%K nonn
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, Feb 25 2010
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