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 A136763 #17 Jan 15 2021 16:30:43
%S A136763 1,1,2,6,1,9,4,2,1,12,9,8,7,7,8,9,11,1,1,2,3,5,9,1,2,4,9,1,3,7,1,3,7,
%T A136763 1,3,10,2,6,1,4,1,3,10,2,9,2,8,2,8,2,9,2,11,3,1,4,1,7,2,11,4,1,6,2,12,
%U A136763 4,1,9,3,1,8,3,1,8,3,1,9,4,2,12,5,2,1,8,4,2,1,7,3,2,1,7,4,2,1,9,5,3,1,1
%N A136763 a(n) = leading digit of n! in base 13.
%H A136763 David A. Corneth, <a href="/A136763/b136763.txt">Table of n, a(n) for n = 0..9999</a>
%e A136763 a(10) = 9 as 10! = 9100926_13 which has leading digit 9. - _David A. Corneth_, Jan 15 2021
%t A136763 Table[First[IntegerDigits[n!,13]],{n,0,100}] (* _Harvey P. Dale_, Dec 20 2015 *)
%o A136763 (PARI) a(n) = digits(n!, 13)[1]; \\ _Michel Marcus_, Jan 27 2015
%Y A136763 Cf. A000142, A136699, A136754, A136755, A136756, A136757, A136758, A136759, A136760, A008905, A136761, A136762, A136764, A136765, A136766.
%K A136763 nonn,easy,base
%O A136763 0,3
%A A136763 _Carl R. White_, Jan 21 2008