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 A165711 #12 Oct 24 2024 14:18:04
%S A165711 1,5,46661,1333735776850284124449081472890437
%N A165711 a(n) = Sum_{k=1..n} k!^k!.
%C A165711 The next term has 250 digits. - _Harvey P. Dale_, Dec 19 2014
%t A165711 s=0;lst={};Do[AppendTo[lst,s+=n!^n! ],{n,1,6,1}];lst
%t A165711 Accumulate[Table[(k!)^k!,{k,5}]] (* _Harvey P. Dale_, Dec 19 2014 *)
%o A165711 (PARI) a(n)=sum(k=1,n,k!^k!) \\ _Charles R Greathouse IV_, Oct 12 2009
%Y A165711 Cf. A165710.
%K A165711 nonn
%O A165711 1,2
%A A165711 _Vladimir Joseph Stephan Orlovsky_, Sep 24 2009