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 A079688 #16 Nov 02 2022 10:29:16 %S A079688 0,0,0,0,1,0,0,1,1,0,0,0,1,0,0,1,0,1,1,2,2,3,1,2,4,2,3,2,4,3,1,1,0,3, %T A079688 4,3,3,3,3,3,4,3,6,2,5,4,3,3,4,3,7,3,5,7,6,6,13,8,8,7,10,4,4,8,10,8, %U A079688 16,10,7,13,6,5,10,7,7,13,11,11,10,4,13,13,16,10,8,15,14,10,18,6,13,12,17,12 %N A079688 Number of 4's in n!. %H A079688 Seiichi Manyama, <a href="/A079688/b079688.txt">Table of n, a(n) for n = 0..10000</a> %H A079688 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>. %F A079688 a(n) = A034886(n) - (A027869(n) + A079680(n) + A079714(n) + A079684(n) + A079690(n) + A079691(n) + A079692(n) + A079693(n) + A079694(n)). - _Reinhard Zumkeller_, Jan 27 2008 %t A079688 DigitCount[#,10,4]&/@(Range[0,100]!) (* _Harvey P. Dale_, Jul 30 2015 *) %Y A079688 Cf. A079714. %Y A079688 Cf. A000142, A137579, A137580. %K A079688 nonn,base,easy %O A079688 0,20 %A A079688 _Cino Hilliard_, Jan 31 2003