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 A174807 #15 Aug 22 2017 15:05:22 %S A174807 0,1,1,1,1,2,1,1,2,3,3,3,3,2,3,4,5,5,5,4,3,5,6,7,5,8,8,6,8,10,10,8,6, %T A174807 7,8,8,10,7,9,9,10,11,10,9,10,9,11,11,11,11,12,13,13,12,14,10,14,17, %U A174807 15,13,13,12,15,14,16,15,12,14,15,15,16,15,15,15,16,13,12,16,17,14,20,20,20 %N A174807 Floor(10^n/4) - A173228(n). %C A174807 a(n) = A055223(n) if n>1. %H A174807 Antonio M. Oller-Marcen, José María Grau, <a href="http://arxiv.org/abs/1002.4175">On the base b expansion of the number of trailing zeros of b^k!</a>, arXiv:1002.4175 [math.NT], 2010, and <a href="https://cs.uwaterloo.ca/journals/JIS/VOL14/Oller/oller3.html">J. Int. Seq. 14 (2011) 11.6.8</a> %K A174807 easy,nonn %O A174807 1,6 %A A174807 _José María Grau Ribas_, Mar 29 2010