a(1) = 1, a(n+1) > a(n) is the smallest multiple of a(n) using only odd digits.

A078221

a(1) = 1, a(n+1) > a(n) is the smallest multiple of a(n) using only odd digits.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =99a(4) =9999a(5) =99999999

External references