Boolean Function - Definition?

[Gordon Royle]

Can anyone please tell me the "official" definition(s?) of boolean function
as used in the OEIS?

I have been trying to reconcile the numbers that I am getting from some
computations with the numbers on the OEIS, but I keep running into
problems.


In some places, a definition basically equivalent to

A boolean function is a function   f: GF(2)^n -> GF(2)

seems to be the right thing.


But then, I can't interpret what "invertible Boolean function" (A001038) means,
nor can I interpret things like A053874 "boolean functions with range k=0..2^n".

What is the "range" of a boolean function?


Thanks

gordon


-- 
Dr. Gordon F Royle, http://www.csse.uwa.edu.au/~gordon, gordon at csse.uwa.edu.au
--