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 A024658 #11 Aug 04 2025 02:17:03 %S A024658 0,1,2,3,4,5,6,7,8,9,30,31,32,33,34,35,36,37,38,39,60,61,62,63,64,65, %T A024658 66,67,68,69,90,91,92,93,94,95,96,97,98,99,320,321,322,323,324,325, %U A024658 326,327,328,329,350,351,352,353,354,355,356,357,358,359,380,381,382,383,384,385 %N A024658 n written in fractional base 10/3. %C A024658 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 A024658 Amiram Eldar, <a href="/A024658/b024658.txt">Table of n, a(n) for n = 0..10000</a> %H A024658 <a href="/index/Ba#base_fractional">Index entries for sequences related to fractional bases</a>. %t A024658 a[n_] := a[n] = If[n == 0, 0, 10 * a[3 * Floor[n/10]] + Mod[n, 10]]; Array[a, 50, 0] (* _Amiram Eldar_, Aug 04 2025 *) %o A024658 (PARI) a(n) = if(n == 0, 0, 10 * a(n\10 * 3) + n % 10); \\ _Amiram Eldar_, Aug 04 2025 %Y A024658 Cf. A245346. %K A024658 nonn,base,easy %O A024658 0,3 %A A024658 _David W. Wilson_