in the bosonic case and in the superstring 10D case it is 16 colours.
Here at PF we have 26 smilies. one for each parameter in the standard model
Your slow post [not Haloscan] to the Reference Frame thread above with Lubos' response brings sequences to my perspective.
Were an 8 to accompany the 5, 13 then Fibonacci numbers come to my mind.
I would bet for a 9. The point is that 10-dimensional and 26 dimensional strings have the same signature module 8. The signature is number of spatial dimensions minus number of time dimensions, so 9-1=8 or 25-1=24. The 25-1=24 is the origin of the work of Borcherds you mentioned in other thread.
In the middle we have 17-1=16, so 18 dimensions and then some unknown object with a group SO(2^9).
But speaking of sequences, I found the one of hexagonal numbers, hidden in my "consider QCD" post.
Separate names with a comma.