45822domain: NAppears in sequencesa(1) = 2, a(n+1) = a(n)-th squarefree number > 1.at n=21A071255a(n) = n*(4*n^2+5*n-3)/2.at n=27A126335a(n) = C(3,n) DELTA C(0,n).at n=30A147724Total volume of the family of rectangular prisms with dimensions p, q and p + q where p divides q, n = p + q and p < q.at n=41A303481