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 A179505 #27 Nov 15 2017 09:38:18
%S A179505 1,1,2,9,56,480,4374,47894,574888,7829424,116392080,1901059512,
%T A179505 33564909432,639562529424,13047133134840,283976169754440,
%U A179505 6563364026374464,160538113862231808,4141949353327046592,112396373034208003008,3199752121483607518080
%N A179505 n-th derivative of x^(x^(x^(x^x))) at x=1.
%H A179505 Alois P. Heinz, <a href="/A179505/b179505.txt">Table of n, a(n) for n = 0..400</a>
%F A179505 E.g.f.: (x+1)^((x+1)^((x+1)^((x+1)^(x+1)))). - _Alois P. Heinz_, Aug 21 2012
%p A179505 a:= n-> n!*coeff(series(subs(x=x+1, x^(x^(x^(x^x))) ), x, n+1), x, n):
%p A179505 seq(a(n), n=0..25); # _Alois P. Heinz_, Aug 21 2012
%t A179505 f[n_] := D[x^(x^(x^(x^x))), {x, n}] /. x -> 1; Array[f, 16, 0]
%t A179505 Range[0, 20]! CoefficientList[ Series[(1 + x)^(1 + x)^(1 + x)^(1 + x)^(1 + x), {x, 0, 20}], x] (* _Robert G. Wilson v_, Feb 03 2013 *)
%Y A179505 Cf. A005727, A179230, A179405, A295105.
%Y A179505 Column k=17 of A215703.
%Y A179505 Column k=5 of A277537.
%K A179505 nonn
%O A179505 0,3
%A A179505 _Robert G. Wilson v_, Jul 17 2010
%E A179505 a(16)-a(20) from _Alois P. Heinz_, Aug 21 2012