a(n) = (10^(2n+1)-1)/3 + 10^n.A332134a(n) = (10^(2n+1)-1)/3 + 10^n.Terms a(0) =4a(1) =343a(2) =33433a(3) =3334333a(4) =333343333a(5) =33333433333External referencesoeis: A332134