a(n) = 4*(10^(2*n+1)-1)/9 - 10^n.A332143a(n) = 4*(10^(2*n+1)-1)/9 - 10^n.Terms a(0) =3a(1) =434a(2) =44344a(3) =4443444a(4) =444434444a(5) =44444344444External referencesoeis: A332143