[seqfan] Re: Number of binary privileged words, etc

Neil Sloane njasloane at gmail.com
Thu Dec 28 11:25:11 CET 2017

>  What is the number of closed words of length n that are not privileged ?

Duuh. It must be simply A226452 - A231208, which will soon be A297184.

I was originally planning to ask for the number of privileged words,
because G. Fici
doesn't say what it is (and doesn't give an A-number), and that
would have been an interesting question.  But while I was typing the message
I found the answer (A231208), and so I just asked the second question, which
of course has a simple answer.

So ignore my previous message from 2 hours ago

Best regards

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com

On Thu, Dec 28, 2017 at 2:47 AM, Neil Sloane <njasloane at gmail.com> wrote:

> Dear Sequence Fans,
> This paper:
> Gabriele Fici, Open and Closed Words, in Giovanni Pighizzini, ed., The
> Formal Language Theory Column, Bulletin of EATCS, 2017,
> http://bulletin.eatcs.org/index.php/beatcs/article/viewFile/508/497
> discusses open words (A297183), closed words (A226452), and
> privileged words (A231208)
> The author also mentions that
> " a privileged word is always closed, but there exist closed words that
> are not privileged, e.g. abab, ababab, ababbabab, etc."
> What is the number of closed words of length n that are not privileged ?

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