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 A143387 #5 Jul 24 2023 10:23:32 %S A143387 3,53,11,17,317,89,1259,2543,7517,16217,15107,33119,60611,671063, %T A143387 2648057 %N A143387 Least prime a(n) such that M(n)*(M(n)+a(n))-1 and M(n)*(M(n)+a(n))+1 are twin primes with M(i)=i-th Mersenne prime A000043(i). %Y A143387 Cf. A000043, A139426, A143385, A143386. %K A143387 hard,more,nonn %O A143387 1,1 %A A143387 _Pierre CAMI_, Aug 11 2008