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 A043426 #13 Apr 24 2021 17:40:49 %S A043426 9,65,72,74,75,76,77,78,79,81,89,97,105,113,121,137,201,265,329,393, %T A043426 457,513,520,522,523,524,525,526,527,529,537,545,553,561,569,576,578, %U A043426 579,580,581,582,583,592,594,595,596,597,598,599 %N A043426 Numbers having two 1's in base 8. %H A043426 Harvey P. Dale, <a href="/A043426/b043426.txt">Table of n, a(n) for n = 1..1000</a> %t A043426 Select[Range[600],DigitCount[#,8,1]==2&] (* _Harvey P. Dale_, Feb 26 2020 *) %Y A043426 Cf. A007094. %K A043426 nonn,base %O A043426 1,1 %A A043426 _Clark Kimberling_