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 A125707 #14 Apr 28 2025 07:14:37
%S A125707 1,2,3,4,5,7,14,15,17,23,32,36,42,309,1384,1588,5631,11226
%N A125707 Numbers k such that A024528(k) is prime.
%t A125707 f=1;Do[p=Prime[n];f=f+1/p;g=Numerator[f];If[PrimeQ[g],Print[{n,p,g}]],{n,1,50}]
%Y A125707 Cf. A024528, A109628.
%K A125707 nonn,hard,more
%O A125707 1,2
%A A125707 _Alexander Adamchuk_, Feb 01 2007
%E A125707 a(14)-a(16) from _Ryan Propper_, Feb 11 2008
%E A125707 a(17)-a(18) from _Michael S. Branicky_, Apr 27 2025