OFFSET
0,3
LINKS
EXAMPLE
(3!)! = 6! = 720 has ten binary digits (1011010000), so a(3) = 10.
PROG
(PARI) a(n) = length(binary(n!!)) \\ Michel Marcus, Jun 02 2013
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Jon E. Schoenfield, Nov 27 2008
STATUS
approved