fixed Latin squares =? A000479(n)
Alec Mihailovs
alec at mihailovs.com
Sun Dec 18 23:06:35 CET 2005
> Let a(n) be A000479(n), the number of latin squares of order n with first
> row 1,2,...,n; given by 1,1,1,2,24,1344,...
>
> Let b(n) be the number of fixed latin squares of order n, i.e., latin
> squares of order n having all 1's on the diagonal.
>
> By direct enumeration, b(n) = a(n) for 1<=n<=5.
>
> Does b(n) = a(n) in general?
Yes. In both cases, all Latin squares of order n can be obtained by
permutations of columns, so the number of all Latin squres of order n is the
number of specified Latin squares multiplied by n! in both cases.
Alec Mihailovs
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