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 A110377 #7 Sep 03 2017 03:30:49
%S A110377 1,2,9,28,205,726,8659,47384,562545,4234330,68588311,483088332,
%T A110377 10699776685,102434734598,2016289908585,24588487650736,
%U A110377 611171244308689,6456997293606738,209020565553571999,2838875160624256460
%N A110377 a(n) = Sum_{r < n, gcd(r,n)=1} n!/r!.
%e A110377 a(6) = 6!(1/1! + 1/5!) = 726.
%p A110377 a:=proc(n) local s,r: s:=0: for r from 1 to n do if gcd(r,n)=1 then s:=s+1/r! else s:=s: fi: od: n!*s end: seq(a(n),n=1..23); # _Emeric Deutsch_, Jul 25 2005
%Y A110377 Cf. A038048, A110276, A110373, A110374.
%K A110377 easy,nonn
%O A110377 1,2
%A A110377 _Amarnath Murthy_, Jul 24 2005
%E A110377 More terms from _Emeric Deutsch_, Jul 25 2005