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 A355060 #13 Jul 01 2025 08:56:19 %S A355060 4,8,9,16,25,27,36,49,125,128,169,256,289,1369,13456,13689,134689 %N A355060 Perfect powers whose digits are in strictly increasing order. %C A355060 I.e., numbers of the form b^k with b > 1 and k > 1 in whose base-10 expansion each digit is greater than the previous digit. %t A355060 perfectPowerQ[n_] := GCD @@ FactorInteger[n][[All, 2]] > 1; (* A001597 *) Select[Range[135000], perfectPowerQ[#] && AllTrue[Differences[IntegerDigits[#]],Positive] &] (* _Stefano Spezia_, Jul 01 2025 *) %Y A355060 Cf. A001597, A009993, A355062. %K A355060 nonn,base,fini,full %O A355060 1,1 %A A355060 _Jon E. Schoenfield_, Jun 16 2022