More or Less, the BBC’s maths and statistics radio show, has been sneakily doing a puzzle on us for the last few weeks. The episodes in the series so far have each been ‘brought to you’, Sesame Street-style, by a different number. But what will the final episode be? Can you crack the integer code and solve the puzzle?

The episodes so far have been brought to you by the numbers 1, 49, 100, 784 and 1444. (It’s not in the OEIS; we’ve checked). You can find out if you’re right when the final episode in the series goes out, on BBC Radio 4 at 4.30pm on Friday 4th October.

On what dates were those episodes aired? Are you saying there are exactly 6 numbers in the sequence?

The first five are all perfect squares, of: 1, 7, 10, 28, and 38. (The first differences between those numbers go down, then up, then down. No obvious pattern.) Since there are exactly 6 terms (I think), I was wondering if there’s a funny pattern related to all 6 numbers together. Or if the date of airing determined the episode’s number. Hmm…

There are six episodes in the series, the first five airing over the last five Fridays, but any inference as to the finiteness or otherwise of the sequence would be pure conjecture.

My good friend David Cushing popped on Facebook messenger to ask me a question: I did tweet it, and I got a lot of good responses. Before I tell you about those, I’ll quickly list the books we mentioned above, that of course a keen 13-year-old already has.

COMPETITION DEADLINE EXTENDED – SEE BELOW! To celebrate the year end, as well as our daily Advent Calendar posts, we’re also running a little competition – last year we did a pun competition, and this year it’s something a bit more crafty – well, it’s a knitting competition in which the knitting is optional.

On what dates were those episodes aired? Are you saying there are exactly 6 numbers in the sequence?

The first five are all perfect squares, of: 1, 7, 10, 28, and 38. (The first differences between those numbers go down, then up, then down. No obvious pattern.) Since there are exactly 6 terms (I think), I was wondering if there’s a funny pattern related to all 6 numbers together. Or if the date of airing determined the episode’s number. Hmm…

There are six episodes in the series, the first five airing over the last five Fridays, but any inference as to the finiteness or otherwise of the sequence would be pure conjecture.

(Edited to correct day of the week)