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 A360258 #33 Feb 17 2023 20:30:31 %S A360258 13,14,20,7,5,10,4,9,63,6,42,1590,1,2,5172911835,974749335,21,26135070 %N A360258 a(n) is the smallest k such that A360097(k) = n. %o A360258 (PARI) %o A360258 a360097(n)=my(k=1);while(isprime(2*n*k-1)||isprime(2*n*k+1),k++);k %o A360258 a(n)=for(i=1,+oo,my(k=a360097(i));if(k==n,return(i))) %Y A360258 Cf. A018252, A124522, A360097. %K A360258 nonn,more %O A360258 1,1 %A A360258 _Jean-Marc Rebert_, Feb 01 2023