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 A074954 #5 Feb 16 2025 08:32:47 %S A074954 9,27,4,8,9,0,8,9,25,2197,27,16,49,0,16,25,25,27,27,36,25,49,27,25, %T A074954 125,27,36,32,225,6889,32,36,49,0,36,100,64,1369,64,49,49,0,484,125, %U A074954 49,289,128,49,81,0,100,196,729,81,64,64,121,0,900,64,125,0,64,100,81,0,1156 %N A074954 Least perfect power b^e such that b^e-n is also a perfect power, or 0 if no such perfect power exists. %C A074954 a(A074981) = 0. %H A074954 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PerfectPower.html">Perfect Power</a>. %e A074954 a(30) = 6889: 30 = 83^2 - 19^3. %Y A074954 Cf. A001597. %K A074954 nonn %O A074954 1,1 %A A074954 _Reinhard Zumkeller_, Oct 10 2002