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 A110386 #6 Sep 03 2017 03:31:21
%S A110386 1,2,7,400,25664160401,
%T A110386 11133592066966265230223312802560009320400030085606006
%N A110386 a(1) = 1, a(2) = a(1) + 1, a(3) = a(2)^2 + a(2) + 1; a(n + 1) = a(n)^n + a(n)^(n-1) + ... + a(n)^2 + a(n) + 1 = {a(n)^(n + 1)-1}/{a(n) - 1}.
%C A110386 The next term is too large to include.
%e A110386 a(3) = 2^2 + 2 + 1 = 7.
%p A110386 a[1]:=1: for n from 1 to 7 do a[n+1]:=sum(a[n]^j,j=0..n) od: seq(a[n],n=1..7); # _Emeric Deutsch_, Jul 31 2005
%K A110386 easy,nonn
%O A110386 1,2
%A A110386 _Amarnath Murthy_, Jul 26 2005
%E A110386 More terms from _Emeric Deutsch_, Jul 31 2005