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 A031487 #9 Jul 04 2021 15:54:40 %S A031487 1,2,3,4,5,6,9,10,11,12,13,14,17,18,19,20,21,22,25,26,27,28,29,30,33, %T A031487 34,35,36,37,38,41,42,43,44,45,46,49,50,51,52,53,54,56,71,73,74,75,76, %U A031487 77,78,81,82,83,84,85,86,89,90,91,92,93,94,97 %N A031487 Numbers whose base-8 representation has the same number of 0's as 7's. %t A031487 Select[Range[100],DigitCount[#,8,0]==DigitCount[#,8,7]&] (* _Harvey P. Dale_, Dec 12 2017 *) %Y A031487 Cf. A007094. %K A031487 nonn,base %O A031487 1,2 %A A031487 _Clark Kimberling_