login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Largest integer with sum of digits n in fractional base 4/3.
3

%I #28 Dec 19 2024 11:45:36

%S 0,1,2,4,5,8,16,17,32,44,80,256,257,344,460,464,620,1472,1964,2620,

%T 2624,3500,6224,8300,11068,11072,26240,34988,46652,262144,262145,

%U 349528,349529,466040,621392,828524,1104700,1532816,3633344,6459280,6459281,11483168,19616912

%N Largest integer with sum of digits n in fractional base 4/3.

%C A largest integer exists since only a finite number of trailing 0 digits are possible, since each is a factor 4/3.

%C Each term k >= 3 has final digit d = k mod 4 which is always d < r where r = k mod 3 (and hence d = 0 or 1), since otherwise (k - r)*4/3 + r would split d into two final digits {d-r, r} for a larger number with the same sum of digits.

%C This sequence is strictly increasing since final digit d = 0 or 1 (and also a(2) = 2) can be incremented so that a(n)+1 is a candidate value for a(n+1).

%H Kevin Ryde, <a href="/A364779/b364779.txt">Table of n, a(n) for n = 0..150</a>

%H Kevin Ryde, <a href="/A364779/a364779_2.c.txt">C Code</a>

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

%o (C) /* See links */

%Y Cf. A024631 (base 4/3), A244041 (sum of digits).

%Y Cf. A357425 (smallest of sum), A364780 (count by sum).

%K nonn,base

%O 0,3

%A _Kevin Ryde_, Aug 13 2023