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 A098651 #9 Jul 07 2021 08:20:28
%S A098651 1,2,6,15,30,39,78,105,910,7735,18655,98605,214415,265031,283309,
%T A098651 313937,373395,432419,440115,441285,497211,573287,658502,1035741,
%U A098651 1198806
%N A098651 Where A098650 reaches a record.
%t A098651 PrimeFactors[n_] := Flatten[ Table[ # [[1]], {1} ] & /@ FactorInteger[ n ]]; f[n_] := Block[{k = n + 1}, If[EvenQ[k], k++ ]; While[ PrimeQ[k] || Union[ PowerMod[ PrimeFactors[n], k - 1, k]] != {1}, k += 2]; k]; a = {1}; b = {9}; Do[ If[ SquareFreeQ[n], c = f[n]; If[c > b[[ -1]], AppendTo[a, n]; AppendTo[b, c]; Print[n]]], {n, 2, 145000}]; a
%Y A098651 Cf. A098650, A098652.
%K A098651 nonn,more
%O A098651 1,2
%A A098651 _Robert G. Wilson v_, Sep 18 2004
%E A098651 a(13)-a(25) from _Amiram Eldar_, Jul 07 2021