710652domain: NAppears in sequencesa(n) = ceiling((n+1/n)^4).at n=28A197903Minimal discriminants d of real quadratic number fields K = Q(sqrt(d)), d > 0, with elementary bicyclic 3-class group Cl_3(K)=(3,3) and second 3-class group M=Gal(F_3^2(K)/K) of assigned coclass cc(M)=1,2,3,4,...at n=2A379524