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A152168
Number of binary digits in (n!)!.
3
1, 1, 2, 10, 80, 661, 5802, 54725, 558704, 6178565, 73840164, 950331113, 13121175977, 193618002604, 3042570732326, 50747501675076, 895651186352884, 16679929313440954, 326936145826028780, 6728526339596831313, 145085354333183129464, 3271200076443827203823
OFFSET
0,3
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
Sequence in context: A100248 A368951 A108486 * A003578 A274276 A152600
KEYWORD
base,nonn
AUTHOR
Jon E. Schoenfield, Nov 27 2008
STATUS
approved