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 A384132 #18 Jun 02 2025 16:24:29 %S A384132 1,2,3,4,5,6,7,8,9,10,11,12,15,16,17,19,21,22,25,27,29,47,58,61,71, %T A384132 113,121 %N A384132 Integers k such that the Diophantine equation x^3 + y^3 + z^3 + w^3 = k^3, where 0 < x < y < z < w has no integer solutions. %C A384132 Conjecture: a(27)=121 is the largest integer whose cube cannot be described as the sum of four distinct positive cubes. %e A384132 13 is not a term because 13^3 = 5^3 + 7^3 + 9^3 + 10^3 = 1^3 + 5^3 + 7^3 + 12^3. %t A384132 a=Select[Range@125,Length@Select[PowersRepresentations[#^3,4,3],0<#[[1]]<#[[2]]<#[[3]]<#[[4]]&]==0&] %Y A384132 Cf. A003327, A383877. %K A384132 nonn,more %O A384132 1,2 %A A384132 _Zhining Yang_, May 20 2025