Panel 1:
The mathematician: You know what would be neat? Changing your name to a de Bruijn sequence. Then you'd have this really long name, but you could claim that any substring was a valid nickname.
Panel 2:
Man: How would you manage that? In order to generate a string containing all 4-letter substrings of a 26 letter alphabet you need 26^4 characters. That's really long.
Panel 3:
The mathematician: Okay, I'd just name myself ttmmtmmmmammhamhaahatahamatamahahaattaatmaathtath*math*hatmtatmmatmhatttattmatthathamttamtmttttmtmamamthaaatataaamaaaahtaahmaahhtahhmahhhthhhmtthmthhmmmhmtmhmmhhmhthmhhhahmtahmmthmmahmhmhahttahtmthtmmhttthttmhtmhhtthhtmahththahhaamtaammaamhtamhmamhhammtammm.
(The other 22 letters aren't that important)
Panel 4:
The mathematician: See? Now I can be nicknamed math, matt, hat, that, or ham.
Man: How do you plan on dealing with the fact that de Bruijn sequences aren't unique?
The mathematician: Be quiet.

Is it possible to make your name the empty set?

# De Bruijn sequences

## 24 January 2007