eklhad@ihnet.UUCP (K. A. Dahlke) (03/13/86)
Concerning 2n by 2n binary matrices with n ones in each row and column, Someone (lost the article) wrote a program to count said matrices, and asked for confirmation. I thought this was an interesting problem, and I too wrote a program to count these matrices. I confirm the results: F(1) = 2 F(2) = 90 F(3) = 297200 F(4) = 116963796250 In addition: F(5) = 6736218287430460752 -- The moon is more important than the sun, because the moon gives us light at night; when we really need it! Karl Dahlke ihnp4!ihnet!eklhad