819330

Appears in sequences

• Number of n-element binary operation tables, out of a total n^n^2 tables, that satisfy the axioms for an Average system. Not culled for isomorphism. The Average system axioms are avg(A,A)=A, avg(A,B)=avg(B,A), avg(avg(A,B),avg(C,D)) = avg(avg(A,C),avg(B,D)).at n=6A111773
• Number of ways to arrange 3 nonattacking triangular rooks on an nXnXn triangular grid.at n=19A193981