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 A110378 #7 Sep 03 2017 03:30:54
%S A110378 1,4,16,81,486,3403,27224,245016,2450160,26951761,323421132,
%T A110378 4204474717,58862646038,882939690570,14127035049120,240159595835041,
%U A110378 4322872725030738,82134581775584023,1642691635511680460
%N A110378 a(n) = Sum_{prime p <= n} n!/p!.
%e A110378 a(6) = 6!(2! + 1/3! + 1/5!) = 486.
%p A110378 a:=proc(n) local s, i: s:=0: for i from 2 to n do if isprime(i)=true then s:=s+1/i! else s:=s: fi: od: n!*s: end: seq(a(n),n=2..23); # _Emeric Deutsch_, Jul 24 2005
%Y A110378 Cf. A038048, A110373, A110374, A110376, A110377.
%K A110378 easy,nonn
%O A110378 2,2
%A A110378 _Amarnath Murthy_, Jul 24 2005
%E A110378 Corrected and extended by _Emeric Deutsch_, Jul 24 2005