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 A072814 #13 Feb 16 2025 08:32:46
%S A072814 2,2,3,2,2,2,3,5,2,2,2,2,2,2,3,7,2,2,2,3,2,5,2,2,2,3,2,2,2,2,3,2,2,2,
%T A072814 2,2,2,2,2,2,3,2,2,2,2,2,3,2,2,2,2,2,3,2,2,2,2,11,2,7,3,2,2,2,2,2,2,3,
%U A072814 2,2,2,5,2,2,2,3,2,2,2,2,2,2,2,2,2,2,2,2,3
%N A072814 Smallest exponents of perfect powers: A001597(n)=A072813(n)^a(n).
%H A072814 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PerfectPower.html">Perfect Power</a>.
%t A072814 {2}~Join~Map[Function[m, Min@ DeleteCases[#, x_ /; x < 2] &@ Table[Boole[k^# == m] # &@ IntegerExponent[m, k], {k, 2, Floor@ Sqrt@ m}]], Select[Range@ 5000, GCD @@ FactorInteger[#][[All, -1]] > 1 &]] (* _Michael De Vlieger_, Dec 08 2016 *)
%K A072814 nonn
%O A072814 1,1
%A A072814 _Reinhard Zumkeller_, Jul 12 2002
%E A072814 Definition corrected by _Daniel Forgues_, Mar 07 2009
%E A072814 Inserted a(1) = 2 by _Gionata Neri_, Dec 08 2016