Numbers k such that there exist two numbers a and b where k = a.b = sigma(a)*phi(b) ("." means concatenation).

A260144

Numbers k such that there exist two numbers a and b where k = a.b = sigma(a)*phi(b) ("." means concatenation).

Terms

    a(0) =1568a(1) =14049280a(2) =140492800a(3) =368089904a(4) =506300928a(5) =1404928000a(6) =14049280000a(7) =124856008704a(8) =140492800000

External references