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 A371191 #5 Mar 14 2024 11:09:32 %S A371191 1372,465125,4879688,6272006419,3533294646441,405211279147678088 %N A371191 Nonsquare terms of A349062. %C A371191 There are no more terms below 10^18. %C A371191 There are 276407671 terms of A349062 below 10^18, of them only 6 are nonsquare numbers. %H A371191 <a href="/index/Pow#powerful">Index entries for sequences related to powerful numbers</a>. %e A371191 1372 = 2^2 * 7^3 is a term since it is a term of A349062 (the gap to the next powerful number, 1444, is 72, which is a record) and it is not a square. %t A371191 seq[max_] := Module[{pows = Union[Flatten[Table[i^2*j^3, {j, 1, Surd[max, 3]}, {i, 1, Sqrt[max/j^3]}]]], gapmax = 0, gap, s = {}}, Do[gap = pows[[k+1]] - pows[[k]]; If[gap > gapmax, gapmax = gap; If[!IntegerQ[Sqrt[pows[[k]]]], AppendTo[s, pows[[k]]]]], {k, 1, Length[pows] - 1}]; s]; seq[10^10] %o A371191 (PARI) lista(mx) = {my(s = List(), gap, gapmax = 0); for(j = 1, sqrtnint(mx, 3), for(i = 1, sqrtint(mx\j^3), listput(s, i^2 * j^3))); s = Set(s); for(k = 1, #s - 1, gap = s[k+1] - s[k]; if(gap > gapmax, gapmax = gap; if(!issquare(s[k]), print1(s[k], ", "))));} %Y A371191 Intersection of A000037 and A349062. %Y A371191 Cf. A227297. %K A371191 nonn,hard,more %O A371191 1,1 %A A371191 _Amiram Eldar_, Mar 14 2024