# The smallest uninteresting number

No posts last week as I was suffering from flu-like symptoms. Seems to have left me with a cough. You know, I should really write a few back-up posts in case of just this type of situation.

Anyhow, I was surprised and pleased to see a bit of maths on QI, the quiz show where the idea is to be interesting rather than right. Stephen Fry asked the panel what the smallest uninteresting number was. Sandi Toksvig spotted that there could be no such thing: if there was, then the number would be interesting for the reason that it was the smallest uninteresting number.

Provided you live a region that allows iPlayer access, the following link will for the next few days take you to the place in the programme:

http://www.bbc.co.uk/i/b017grcc/?t=27m19s

If you are unable to watch, then the definition they use for smallest uninteresting number is the smallest integer that does not appear in the The On-Line Encyclopedia of Integer Sequences. The number turns out to be 12407. Of course, if you are reading this in the future, the number may be different as someone may have found a use for 12407 in a sequence. During the programme, Stephen Fry relates the story of 1729. The clip is worth watching for the audience’s reaction to the story. At this point Alan Davies mentions that he feels like Homer Simpson. A better comparison would have been Philip J. Fry, the lead character in the Simpson’s follow-up, Futurama. As the head writer had a PhD in maths Futurama contains many maths jokes and features several references to 1729. Eg, Zapp Brannigan’s ship has 1729 on it and Bender, the robot, is son number 1729 as can be seen in this picture I’ve shamelessly lifted from the Wolfram website:

If you object to this dumbing-down and instead want some real hard core analysis of the OEIS, then have a look at the preprint, http://arxiv.org/pdf/1101.4470v2, on the arXiv.