a(1) = 1; thereafter a(n+1) > a(n) is the smallest multiple of a(n) using only odd digits but not divisible by 9.

A329764

a(1) = 1; thereafter a(n+1) > a(n) is the smallest multiple of a(n) using only odd digits but not divisible by 9.

Terms

    a(0) =1a(1) =3a(2) =15a(3) =75a(4) =375a(5) =9375a(6) =159375a(7) =71559375

External references