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 A023760 #22 Feb 15 2019 01:54:36 %S A023760 0,1,2,3,4,5,8,9,10,12,13,14,15,16,20,21,32,36,37,40,41,42,48,52,53, %T A023760 56,57,58,60,61,62,63,64,80,84,85,128,144,148,149,160,164,165,168,169, %U A023760 170,192,208,212,213,224,228,229,232,233,234,240,244,245,248 %N A023760 Nialpdromes: digits in base 4 are in nonincreasing order. %H A023760 Vincenzo Librandi, <a href="/A023760/b023760.txt">Table of n, a(n) for n = 1..1001</a> (adapted to the new offset from _Bruno Berselli_) %t A023760 Select[Range[0, 4000], Max[Differences[IntegerDigits[#, 4]]] <= 0 &] (* _Vincenzo Librandi_, Dec 26 2012 *) %t A023760 Select[Range[0, 250], GreaterEqual@@IntegerDigits[#, 4] &] (* _Ray Chandler_, Jan 06 2014 *) %Y A023760 Cf. A023786 (subset), A031999 (slightly different version). %K A023760 nonn,base,easy %O A023760 1,3 %A A023760 _Olivier Gérard_