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 A275588 #14 Oct 13 2017 05:05:39
%S A275588 1,1,2,16,429496729600000000000000000000000000000000
%N A275588 a(1) = 1; thereafter a(n) = (Sum_{k=1..n-1} a(k)) ^ Product_{k=1..n-1} a(k).
%C A275588 a(6) is roughly 10^(5.72199*10^44).
%e A275588 a(4) = (a(1) + a(2) + a(3)) ^ (a(1)*a(2)*a(3)) = (1 + 1 + 2)^(1*1*2) = 4^2 = 16.
%t A275588 a[1] = 1; a[n_] := a[n] = Sum[a[k], {k, n - 1}]^Product[a[k], {k, n - 1}]; Table[a[n], {n, 0, 5}] (* _Michael De Vlieger_, Aug 04 2016 *)
%o A275588 (PARI) a(n) = if(n==1, 1, if(n>1, sum(k=1, n - 1, a(k)) ^ prod(k=1, n - 1, a(k))))
%Y A275588 Cf. A275587.
%K A275588 nonn
%O A275588 1,3
%A A275588 _Rick L. Shepherd_, Aug 02 2016