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 A136758 #15 Jan 15 2021 16:33:18
%S A136758 1,1,2,6,3,2,2,2,2,3,4,6,1,3,6,1,4,1,3,1,4,1,5,2,1,4,2,1,5,3,2,1,5,3,
%T A136758 2,1,1,1,5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,2,2,2,3,3,4,5,6,1,1,1,2,3,4,5,
%U A136758 1,1,2,3,4,1,1,2,3,5,1,2,3,5,1,2,3,6,1,3,5,1,2,4,1,2,4,1,2,5,1,2
%N A136758 a(n) = leading digit of n! in base 7.
%H A136758 David A. Corneth, <a href="/A136758/b136758.txt">Table of n, a(n) for n = 0..9999</a>
%e A136758 a(10) = 4 as 10! = 42562410_7 which has leading digit 4. - _David A. Corneth_, Jan 15 2021
%t A136758 f[n_]:=First[IntegerDigits[n!,7]]; lst={};Do[AppendTo[lst,f[n]],{n,0,2*5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 14 2009 *)
%t A136758 First[IntegerDigits[#,7]]&/@(Range[0,100]!) (* _Harvey P. Dale_, Nov 23 2013 *)
%o A136758 (PARI) a(n) = digits(n!, 7)[1]; \\ _Michel Marcus_, Jan 27 2015
%Y A136758 Cf. A000142, A136694, A136754, A136755, A136756, A136757, A136759, A136760, A008905, A136761, A136762, A136763, A136764, A136765, A136766.
%K A136758 base,easy,nonn
%O A136758 0,3
%A A136758 _Carl R. White_, Jan 21 2008