Numbers k such that sigma(k)/k - 1 equals (sigma(m)/m - 1)^2 for some m <= k.
A381321
Numbers k such that sigma(k)/k - 1 equals (sigma(m)/m - 1)^2 for some m <= k.
Terms
- a(0) =1a(1) =6a(2) =28a(3) =216a(4) =360a(5) =496a(6) =2016a(7) =8128a(8) =16758a(9) =1571328a(10) =1935360a(11) =2678400a(12) =33550336a(13) =54758400a(14) =101382400a(15) =1685013120
External references
- oeis: A381321