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%I #9 Jul 06 2019 15:37:28
%S 1,2,197573,43600856616158353989522412378215477
%N Number of digits in factorial numbers of the form: (n!^n!)!.
%C (1!^1!)!=1 -> 1 digit; (2!^2!)!=24 -> 2 digits; (3!^3!)!=veryverylargenumber -> 197573 digits; (4!^4!)!=?!...
%C From _Jon E. Schoenfield_, Dec 21 2008: (Start)
%C (3!^3!)! = (6^6)! = 46656! = 6.8964...*10^197572
%C (4!^4!)! = (24^24)! = 1333735776850284124449081472843776! = 1.1463...*10^43600856616158353989522412378215476. (End)
%t a[n_]:=Length[IntegerDigits[(n!^n!)! ]];
%K nonn,base
%O 1,2
%A _Vladimir Joseph Stephan Orlovsky_, Dec 05 2008
%E a(4) from _Jon E. Schoenfield_, Dec 21 2008