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 A024632 #16 Jul 31 2025 03:51:10 %S A024632 0,1,2,3,4,20,21,22,23,24,40,41,42,43,44,210,211,212,213,214,230,231, %T A024632 232,233,234,400,401,402,403,404,420,421,422,423,424,440,441,442,443, %U A024632 444,2110,2111,2112,2113,2114,2130,2131,2132,2133,2134,2300,2301,2302,2303 %N A024632 n written in fractional base 5/2. %C A024632 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 A024632 Alois P. Heinz, <a href="/A024632/b024632.txt">Table of n, a(n) for n = 0..10000</a> %H A024632 <a href="/index/Ba#base_fractional">Index entries for sequences related to fractional bases</a>. %p A024632 a:= proc(n) `if`(n<1, 0, irem(n, 5, 'q')+a(2*q)*10) end: %p A024632 seq(a(n), n=0..53); # _Alois P. Heinz_, May 14 2021 %t A024632 a[n_] := a[n] = If[n == 0, 0, 10 * a[2 * Floor[n/5]] + Mod[n, 5]]; Array[a, 100, 0] (* _Amiram Eldar_, Jul 30 2025 *) %o A024632 (PARI) a(n) = if(n == 0, 0, 10 * a(n\5 * 2) + n % 5); \\ _Amiram Eldar_, Jul 30 2025 %Y A024632 Cf. A245341. %K A024632 nonn,base,easy %O A024632 0,3 %A A024632 _David W. Wilson_