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 A024653 #11 Aug 02 2025 06:26:12 %S A024653 0,1,2,3,4,5,6,7,8,50,51,52,53,54,55,56,57,58,510,511,512,513,514,515, %T A024653 516,517,518,560,561,562,563,564,565,566,567,568,5120,5121,5122,5123, %U A024653 5124,5125,5126,5127,5128,5170,5171,5172,5173,5174,5175,5176,5177,5178 %N A024653 n written in fractional base 9/5. %C A024653 To represent a number in base b, if a digit exceeds b-1, subtract b and carry 1. In fractional base a/b, subtract a and carry b. %H A024653 Amiram Eldar, <a href="/A024653/b024653.txt">Table of n, a(n) for n = 0..10000</a> %H A024653 <a href="/index/Ba#base_fractional">Index entries for sequences related to fractional bases</a>. %t A024653 a[n_] := a[n] = If[n == 0, 0, 10 * a[5 * Floor[n/9]] + Mod[n, 9]]; Array[a, 50, 0] (* _Amiram Eldar_, Aug 02 2025 *) %o A024653 (PARI) a(n) = if(n == 0, 0, 10 * a(n\9 * 5) + n % 9); \\ _Amiram Eldar_, Aug 02 2025 %Y A024653 Cf. A245354. %K A024653 nonn,base,easy %O A024653 0,3 %A A024653 _David W. Wilson_