182449domain: NAppears in sequencesa(1)=a(2)=a(3)=1; for n>3, a(n)=(a(n-1)*a(n-2)+a(n-1)+a(n-2))/a(n-3).at n=12A072881Let p(n) be the n-th composite squarefree number. a(n) is the smallest integer q that forms a pure idempotent product.at n=35A325945