This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A173970 #10 Sep 08 2022 08:45:51
%S A173970 5,7,23,47,53,73,157,173,211,233,257,263,353,373,563,593,607,619,647,
%T A173970 653,733,947,977,1069,1097,1103,1123,1187,1223,1283,1367,1433,1453,
%U A173970 1459,1493,1499,1511,1613,1709,1747,1753,1759,1789,1889,1907,2099,2161,2287
%N A173970 Primes p such that 2*p-NextPrime are prime numbers.
%C A173970 2*5-7=3, 2*7-11=3, 2*23-29=17,..
%H A173970 Robert Israel, <a href="/A173970/b173970.txt">Table of n, a(n) for n = 1..10000</a>
%p A173970 P:= select(isprime, [2,seq(i,i=1..10000,2)]):
%p A173970 Q:= 2*P[1..-2]-P[2..-1]:
%p A173970 P[select(t -> isprime(Q[t]),[$1..nops(Q)])]; # _Robert Israel_, Jul 03 2019
%t A173970 lst={};Do[p=Prime[n];If[PrimeQ[2*p-Prime[n+1]],AppendTo[lst,p]],{n,6!}];lst
%t A173970 Select[Prime[Range[400]],PrimeQ[2#-NextPrime[#]]&] (* _Harvey P. Dale_, May 04 2021 *)
%o A173970 (Magma) [p:p in PrimesUpTo(2500)| IsPrime(2*p-NextPrime(p))]; // _Marius A. Burtea_, Jul 03 2019
%K A173970 nonn
%O A173970 1,1
%A A173970 _Vladimir Joseph Stephan Orlovsky_, Mar 03 2010