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%I #3 May 11 2007 03:00:00
%S 1,1,1,5,59,3470
%N Number of inequivalent (under the "inversion of variables") monotone Boolean nondegenerate functions of n variables.
%C We define the "inversion of variables", i, by (i.f)(x1,...,xn)=1+f(1+x1,...,1+xn). Note that {i,identity function} is a group. It turns out that if f is a monotone function, then i.f is also a monotone function. f is equivalent to g if f=g or f=i.g.
%e a(2)=1 because f(x1,x2)=x1x2 is equivalent to g(x1,x2)=x1+x2+x1x2 and there are no more monotone Boolean nondegenerate functions of 2 variables.
%K nonn,more
%O 0,4
%A Alan Veliz-Cuba (alanavc(AT)vt.edu), Jun 16 2006