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 A271653 #21 Sep 08 2022 08:46:16
%S A271653 11,31,47,61,113,127,179,241,307,419,433,449,491,853,881,1063,1153,
%T A271653 1201,1289,1487,1823,1997,2011,2027,2333,2441,2459,2647,2851,2927,
%U A271653 3041,3449,3491,3853,4057,4241,4259,4397,4423,4679,4721,5003,5179,5233,5569,5653,5867,6397,6481,6661
%N A271653 Primes of the form 2*prime(2k) - prime(k).
%e A271653 For n=1, 2*prime(2*2)-prime(2) = 2*7-3 = 11 is prime when k=2.
%e A271653 For n=2, 2*prime(2*4)-prime(4) = 2*19-7 = 31 is prime when k=4.
%p A271653 A271653:=n->`if`(isprime(2*ithprime(2*n)-ithprime(n)), 2*ithprime(2*n)-ithprime(n), NULL): seq(A271653(n), n=1..600); # _Wesley Ivan Hurt_, Apr 17 2016
%t A271653 Select[Table[2*Prime[2 k] - Prime[k], {k, 0, 100}], PrimeQ]
%o A271653 (PARI) lista(nn) = for(n=1, nn, if(isprime(p=2*prime(2*n)-prime(n)), print1(p, ", "))); \\ _Altug Alkan_, Apr 13 2016
%o A271653 (Magma) [a: n in [0..400] | IsPrime(a) where a is 2*NthPrime(2*n) - NthPrime(n)]; // _Vincenzo Librandi_, Apr 15 2016
%Y A271653 Cf. A272042.
%K A271653 nonn
%O A271653 1,1
%A A271653 _Andres Cicuttin_, Apr 11 2016