%I #22 Jul 20 2024 20:03:13
%S 1,2,15,3814279
%N a(n) = floor(e^e^ ... ^e), with n e's.
%C The next term is too large to include.
%C From _Vladimir Reshetnikov_, Apr 27 2013. (Start)
%C a(4) = 2331504399007195462289689911...2579139884667434294745087021 (1656521 decimal digits in total), given by initial segment of A085667.
%C a(5) has more than 10^10^6 decimal digits.
%C a(6) has more than 10^10^10^6 decimal digits. (end)
%p p:= n-> `if`(n=0, 1, exp(1)^p(n-1)):
%p a:= n-> floor(p(n)):
%p seq(a(n), n=0..3); # _Alois P. Heinz_, Jul 20 2024
%t Floor[NestList[Exp, 1, 3]] (* _Vladimir Reshetnikov_, Apr 29 2013 *)
%o (PARI) A056072(n,f=floor)=f(exp(if(n>0,A056072(n-1,x->x)))) \\ [_M. F. Hasler_, May 01 2013]
%Y Cf. A001113, A004002, A003417, A064107, A159825, A073226, A073227, A085667, A225064, A225053.
%K nonn
%O 0,2
%A _Robert G. Wilson v_, Jul 26 2000