Least number that reaches 1 after n iterations of the map k -> usigma(k)/ud(k) if ud(k) | usigma(k), and k -> 1 otherwise, where ud(k) is the number of unitary divisors of k (A034444) and usigma(k) is their sum (A034448).
A334816
Least number that reaches 1 after n iterations of the map k -> usigma(k)/ud(k) if ud(k) | usigma(k), and k -> 1 otherwise, where ud(k) is the number of unitary divisors of k (A034444) and usigma(k) is their sum (A034448).
Terms
- a(0) =1a(1) =2a(2) =3a(3) =5a(4) =9a(5) =17a(6) =43a(7) =137a(8) =281a(9) =673a(10) =2401a(11) =4801a(12) =9601a(13) =170761a(14) =341521a(15) =683041a(16) =5114881a(17) =31846081a(18) =131955841a(19) =1985902081a(20) =7545868801
External references
- oeis: A334816