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 A263540 #6 Oct 31 2015 15:02:20 %S A263540 1,1,1,1,1,17,25,37,265,5,93,2395,1443,3935,2757,5865 %N A263540 Values of k in A263539. %o A263540 (PARI) terms=12; p=1; for(n=1, terms, q=p+2; while(!ispseudoprime(q), q+=2*p); print1((q-2)/p, ", "); p*=q) %Y A263540 Cf. A263539, A258081. %K A263540 nonn,hard,more %O A263540 1,6 %A A263540 _Jeppe Stig Nielsen_, Oct 20 2015