4293918720domain: NAppears in sequencesa(n) = 4^n - n^5.at n=16A024041Number of non-commutative closed binary operations on a set of order n.at n=3A079182Number of groupoids of order n with no identity element.at n=4A175882a(n) = 4^n - n*2^n.at n=16A186947