Mirror Set, take-2 from sci.math

[Hugo Pfoertner]

SeqFans,

found this morning in sci.math:
"Mirror Set, take-2" by Akira Bergman
http://groups.google.com/group/sci.math/msg/04826c1ffa6f6187

I don't know if he re-invents something well known, but at least he
found two sequences. The first one is well known:

Product of the first n factorials 1!*2!*3!*....*n!, which is
http://www.research.att.com/~njas/sequences/A000178
(two more terms might fit into the OEIS STU lines)

and the second is (product of first n factorials)/2^n 

n  A000178(n)
      A000178(n)/2^n
1  1  1/2
2  2  1/2
3  12  3/2
4  288  18
5  34560 1080
6  24883200  388800
7  125411328000  979776000
8  5056584744960000  19752284160000
9  1834933472251084800000  3583854437990400000
10 6658606584104736522240000000  6502545492289781760000000
11 265790267296391946810949632000000000 
129780403953316380278784000000000
12 127313963299399416749559771247411200000000000 
31082510571142435729872991027200000000000
13 792786697595796795607377086400871488552960000000000000  96
775719921361913526291148242293882880000000000000

18,1080,388800,... is not in OEIS

Hugo Pfoertner