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 A364948 #4 Aug 24 2023 10:33:42 %S A364948 4,121,2548735225 %N A364948 Perfect powers that are equal to the sum of the first k perfect powers > 1 for some k. %e A364948 121 is a term because 121 = 11^2 = 4 + 8 + 9 + 16 + 25 + 27 + 32 = 2^2 + 2^3 + 3^2 + 2^4 + 5^2 + 3^3 + 2^5. %t A364948 Select[Accumulate[Select[Range[3723875], GCD @@ FactorInteger[#][[All, 2]] > 1 &]], GCD @@ FactorInteger[#][[All, 2]] > 1 &] %Y A364948 Cf. A001597, A013918, A013921, A013932. %K A364948 nonn,bref,hard,more %O A364948 1,1 %A A364948 _Ilya Gutkovskiy_, Aug 14 2023