The number of initial values <= 10^n whose trajectory under the iteration x -> A306938(x) reaches 1.

A306971

The number of initial values <= 10^n whose trajectory under the iteration x -> A306938(x) reaches 1.

Terms

    a(0) =7a(1) =23a(2) =63a(3) =175a(4) =459a(5) =1349a(6) =3506a(7) =8820a(8) =21897

External references