OFFSET
0,4
FORMULA
a(n) = floor(log(n!*2^n)/log(10)) + 1.
MATHEMATICA
Table[IntegerLength[2^n n!], {n, 0, 70}] (* Harvey P. Dale, May 03 2024 *)
PROG
(PARI) a(n) = log(n!*2^n)\log(10) + 1; \\ Michel Marcus, Oct 23 2020
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Benoit Cloitre, Mar 01 2002
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Oct 23 2020
STATUS
approved