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 A136766 #26 Jan 15 2021 16:35:43
%S A136766 1,1,2,6,1,7,2,1,9,5,3,2,1,1,1,1,1,1,1,1,2,2,3,5,8,12,1,2,3,6,13,1,3,
%T A136766 6,13,1,4,9,1,3,8,1,3,10,1,4,14,2,7,1,4,14,2,9,2,7,1,5,1,4,1,4,1,3,15,
%U A136766 4,1,4,1,5,1,6,1,7,2,10,3,15,4,1,7,2,11,3,1,6,2,11,4,1,7,2,1,5,2,12,4,1,11
%N A136766 a(n) = leading digit of n! in base 16.
%H A136766 David A. Corneth, <a href="/A136766/b136766.txt">Table of n, a(n) for n = 0..9999</a> (first 1001 terms from Robert G. Wilson v)
%e A136766 For n=5, 5! = 5*4*3*2*1 = 120 in base 10, which is 78 in hexadecimal (7*16 + 8*1), so a(5) = 7. - _Michael B. Porter_, Sep 20 2016
%t A136766 Array[ IntegerDigits[#!, 16][[1]] &, 1001, 0] (* _Robert G. Wilson v_, Sep 20 2016 *)
%t A136766 Table[Floor[#/16^Floor@ Log[16, #]] &[n!], {n, 0, 98}] (* _Michael De Vlieger_, Sep 20 2016 *)
%o A136766 (PARI) a(n) = digits(n!, 16)[1]; \\ _Michel Marcus_, Jan 27 2015
%Y A136766 Cf. A000142, A136702, A136754, A136755, A136756, A136757, A136758, A136759, A136760, A008905, A136761, A136762, A136763, A136764, A136765.
%K A136766 nonn,easy,base
%O A136766 0,3
%A A136766 _Carl R. White_, Jan 21 2008