The group number function: the number of groups of a given order
The group number function: the number of groups of a given order

John Conway, Princeton University
Fine Hall 224
The group number, gnu(n) of n, is defined to be the number of groups of order n. It is now known for all n < 211. I shall discuss the peculiar properties of this function and of the related function moa(n), defined to be the least number N for which gnu(N)=n.