No of sudokus, A107739

[Shripad M. Garge]

Dear Sloane,

We do not always have to consider the boxe in Sudoku to be a square. For
instance, a 6 X 6 sudoku may be constructed with 3 X 2 boxes in it, 2 in
each rwo and 3 in each column. I have drawn one below. The number of all
such sudokus, with 3 X 2 boxes or 2 X 3 boxes will be a(6) and the number
of standard 9 X 9 sudokus will be a(9). The term a(p) will be then 1, as
there is no possibility for smaller boxes in it. 

I can not do the comutations here, but will someone compute this sequence
and put on OEIS?

Regards,
Shripad. 


 |---|---|---||---|---|---|
 | 1 | 2 | 3 || 4 | 5 | 6 |
 |---|---|---||---|---|---|
 | 4 | 5 | 6 || 1 | 2 | 3 |
 |---|---|---||---|---|---|
 |---|---|---||---|---|---|
 | 2 | 3 | 1 || 5 | 6 | 4 |
 |---|---|---||---|---|---|
 | 5 | 6 | 4 || 2 | 3 | 1 |
 |---|---|---||---|---|---|
 |---|---|---||---|---|---|
 | 3 | 1 | 2 || 6 | 4 | 5 |
 |---|---|---||---|---|---|
 | 6 | 4 | 5 || 3 | 1 | 2 |
 |---|---|---||---|---|---|





On Thu, 11 Aug 2005, N. J. A. Sloane wrote:

:: 
:: 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
::