681856domain: NAppears in sequencesNumber of (w,x,y,z) with all terms in {0,...,n} and at least one of these conditions holds: w<R, x<R, y<R, z>R, where R=max{w,x,y,z}-min{w,x,y,z}.at n=28A212752Numbers n for which n = phi(x)*phi(y), where n = x + y and phi(x) is the Euler totient function of x.at n=38A273800