A120618 Number of inequivalent (under "inversion of variables") monotone Boolean functions of n or fewer variables.

1, 2, 4, 12, 90, 3831

Offset: 0

Author

Alan Veliz-Cuba (alanavc(AT)vt.edu), Jun 18 2006

Keywords

• nonn
• more

Comments

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.

Examples

			a(1)=2 because m(x)=0,n(x)=1,k(x)=x are the three monotone Boolean functions (of 1 or fewer variables) and m,n are equivalent.
		

Crossrefs

Cf. A120608, A120587, A006602.