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 A190941 #18 Feb 15 2020 23:29:32
%S A190941 0,1,3,4,5,7,9,11,13,14,15,17,18,19,21,23,25,27,29,31,33,35,37,39,41,
%T A190941 43,45,46,47,49,50,51,53,55,57,59,60,61,63,64,65,67,69,71,73,75,77,79,
%U A190941 81,83,85,87,89,91,93,95,97,99,101,103,105,107,109,111,113,115,117,119,121,123,125,127,129,131,133,135,137,139,141,143,145,146,147,149,150,151,153,155,157,159,160,161,163,164,165,167,169,171,173,175,177,179,181,183,185
%N A190941 Partial sums of A190592.
%C A190941 Compare with obvious base-2 analog. What is the general base-k formula?
%H A190941 Michael De Vlieger, <a href="/A190941/b190941.txt">Table of n, a(n) for n = 0..10000</a>
%F A190941 a(n) = Sum_{i=0..n} (maximal digit in base-3 expansion of i).
%F A190941 a(n) = 3n + O(n^0.631). - _Charles R Greathouse IV_, Aug 21 2011
%t A190941 Accumulate@ Array[Max@ IntegerDigits[#, 3] &, 105, 0] (* _Michael De Vlieger_, Feb 15 2020 *)
%K A190941 nonn,easy,base
%O A190941 0,3
%A A190941 _Jonathan Vos Post_, May 24 2011