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 A143385 #5 Jul 24 2023 10:24:19 %S A143385 1,53,11,17,317,89,737,2543,1247,6209,15107,33119,60611,671063,2648057 %N A143385 Least 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. %e A143385 (2^2-1)*(2^2-1+1)-1=11 prime, 11 and 13 twin primes, 2^2-1=M(1) so a(1)=1 %Y A143385 Cf. A139426. %K A143385 hard,more,nonn %O A143385 1,2 %A A143385 _Pierre CAMI_, Aug 11 2008