No of sudokus, A107739

[N. J. A. Sloane]

Sequence A107739, submitted by Richard McNair, has a long entry,
beginning:

%I A107739
%S A107739 1,2,288,6670903752021072936960
%N A107739 Number of valid sudokus of order 2n.
%H A107739 Wikipedia, <a href="http://en.wikipedia.org/wiki/Sudoku">Sudoku</a>
...

The definition looks wrong to me, but I don't
know anything about these puzzles.  I'm guessing that
the description should really "the number of order n"
and that 6670903752021072936960 is the number of order 3,
which is the standard 9 X 9 puzzle seen in newspapers.

Can someone who knows about these things confirm this?

Neil