667 - “fax number of the beast” - that was funny ;) The thing about mathematics is that it can tickle your brain - in a creative way.

It's becoming increasingly difficult these days, with so many things competing for your attention and "brain-deadening" you. It was a wonderful thing to be bored and play around with math. My favorite moments were the epiphany - that there is some hidden connection between math areas or something got new meaning.

I don’t know anybody who would both appreciate the fax number of the beast joke and not turn it into a conversation about 617 being the real fax number of the beast according to most manuscripts.

As it doesn't seem to be linked, here is Hofstadter Q-sequence https://oeis.org/A005185

I can't tell which of Chai Wah Wu's submissions the interviewer was referring to. https://oeis.org/search?q=Chai%20Wah%20Wu&fmt=short&sort=cre...

Strange. In the article A138563 is described as a sequence of prime numbers that contain the substring 667. But these are obviously not prime numbers. Having a look at https://oeis.org/A138563 reveals that these are simply any numbers containing the substring.