256011840domain: NAppears in sequencesNonprime-power sigma-perfect numbers: numbers n such that NPPSigma(n)=2*n, where, if n=Product p_i^r_i then NPPSigma(n)=Product{Sum p_i^s_i, s_i is not a prime number, 0<=s_i<=r_i}.at n=4A099723