[seqfan] Re: A new sequence counting the number of distinct languages recognized by DFAs

[brad klee]

> I hope it may help understanding my idea. Again, I suggest focusing
> initially on the "equivalent DFAs" part rather on the choosing such or
> such definition of the DFAs, since the most interesting part of the
> compuation is there IMHO.

Madhusudan Parthasarathy at University of Illinois has some nice 
teaching materials online: 

https://courses.grainger.illinois.edu/cs373/sp2010/lectures/

Working from a few of these lectures, I calculated three terms 
in agreement with Thomas, and made notes here:

https://community.wolfram.com/groups/-/m/t/3233849

Arthur independently agreed about up to four terms (of the 
proposed, slower growing sequence with no floating edges), 
so I think the candidate now has good quality assurance.  

Equivalence calculations are indeed interesting, and there's 
potentially more optimization to do using standard algorithms. 

What's more interesting to me as a result of this recent 
experiment is how many different equivalent regex's can 
describe the same DFA-produced regular language. 

In the continuation, I'm curious about algorithms that 
compare and reduce regex over finite alphabets. Would 
be nice to know more about that... 



Cheers, 






--Brad