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 A023786 #13 Feb 09 2019 02:24:10 %S A023786 0,1,2,3,4,8,9,12,13,14,36,52,56,57,228 %N A023786 Katadromes: digits in base 4 are in strict descending order. %C A023786 No more terms are possible because, although infinitely many numbers have base 4 digits in descending order, like 256, none beyond 228 can have them in strictly descending order. - _Alonso del Arte_, Feb 08 2019 %e A023786 228 in base 4 is 3210. Since those digits are in strictly descending order, 228 is in the sequence. %e A023786 229 in base 4 is 3211. Although those digits are in descending order, the repeated digit 1 means 229 is not in the sequence. %t A023786 Select[Range[0, 255], Max[Differences[IntegerDigits[#, 4]]] < 0 &] (* _Harvey P. Dale_, Dec 15 2014 *) %Y A023786 Cf. A023760, A031999. %K A023786 nonn,base,fini,full,easy %O A023786 1,3 %A A023786 _Olivier Gérard_