Numbers k such that phi(k) divides sigma(k) and sigma(k)/k > sigma(m)/m for all m < k.

A007668

Numbers k such that phi(k) divides sigma(k) and sigma(k)/k > sigma(m)/m for all m < k.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =12a(4) =840a(5) =332640

External references