Let sigma_m(n) be result of applying the sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m(n) = k*n; sequence gives log_2 of the (2,2)-perfect numbers.
A019280
Let sigma_m(n) be result of applying the sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m(n) = k*n; sequence gives log_2 of the (2,2)-perfect numbers.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =6a(4) =12a(5) =16a(6) =18a(7) =30a(8) =60
External references
- oeis: A019280