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 A023746 #17 Oct 18 2018 21:41:28 %S A023746 0,1,2,3,5,6,7,10,11,15,21,22,23,26,27,31,42,43,47,63,85,86,87,90,91, %T A023746 95,106,107,111,127,170,171,175,191,255,341,342,343,346,347,351,362, %U A023746 363,367,383,426,427,431,447,511,682,683,687,703,767,1023,1365,1366 %N A023746 Plaindromes: numbers whose digits in base 4 are in nondecreasing order. %H A023746 Vincenzo Librandi, <a href="/A023746/b023746.txt">Table of n, a(n) for n = 1..500</a> %t A023746 Select[Range[0,1366],LessEqual@@IntegerDigits[#,4]&] (* _Ray Chandler_, Jan 06 2014 *) %K A023746 nonn,base,easy %O A023746 1,3 %A A023746 _Olivier Gérard_ %E A023746 Offset set to 1 by _Ray Chandler_, Jan 06 2014