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 A133376 #26 Jan 17 2024 12:19:05
%S A133376 2,8,4096,1152921504606846976,
%T A133376 2348542582773833227889480596789337027375682548908319870707290971532209025114608443463698998384768703031934976
%N A133376 a(n) = (...((2^3)^4)^...)^n.
%C A133376 Another kind of exponential factorial.
%C A133376 See cross-references for other possible definitions of exponential factorials.
%C A133376 Some other terms of the sequence can be computed, but they are quite large and it wouldn't be very convenient to display them.
%C A133376 The next term has 759 digits. - _Harvey P. Dale_, Oct 22 2019
%H A133376 Alois P. Heinz, <a href="/A133376/b133376.txt">Table of n, a(n) for n = 2..7</a>
%F A133376 a(n) = 2^(n!/2) for n >= 2. - _Karl W. Heuer_, Nov 25 2014
%e A133376 a(4) = 4096, as (2^3)^4 = 4096.
%p A133376 expfact:= proc(n::integer) local i,res; res:=2; for i from 3 to n do res:=(res)^i od; res end proc; seq(expfact(n), n=2..7);
%p A133376 # second Maple program:
%p A133376 a:= proc(n) option remember;
%p A133376 `if`(n<3, n, a(n-1)^n)
%p A133376 end:
%p A133376 seq(a(n), n=2..6); # _Alois P. Heinz_, Jan 17 2024
%t A133376 nxt[{n_,a_}]:={n+1,a^(n+1)}; NestList[nxt,{2,2},4][[All,2]] (* _Harvey P. Dale_, Oct 22 2019 *)
%Y A133376 Cf. A124075, A049384.
%K A133376 nonn
%O A133376 2,1
%A A133376 Pierre Karpman (pierre.karpman(AT)laposte.net), Oct 28 2007