A024658 - OEIS

%I #11 Aug 04 2025 02:17:03

%S 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 66,67,68,69,90,91,92,93,94,95,96,97,98,99,320,321,322,323,324,325,

%U 326,327,328,329,350,351,352,353,354,355,356,357,358,359,380,381,382,383,384,385

%N n written in fractional base 10/3.

%C 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 Amiram Eldar, <a href="/A024658/b024658.txt">Table of n, a(n) for n = 0..10000</a>

%H <a href="/index/Ba#base_fractional">Index entries for sequences related to fractional bases</a>.

%t 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 (PARI) a(n) = if(n == 0, 0, 10 * a(n\10 * 3) + n % 10); \\ _Amiram Eldar_, Aug 04 2025

%Y Cf. A245346.

%K nonn,base,easy

%O 0,3

%A _David W. Wilson_