a(n) = 4*(10^(2*n+1) - 1)/9 + 4*10^n.A332148a(n) = 4*(10^(2*n+1) - 1)/9 + 4*10^n.Terms a(0) =8a(1) =484a(2) =44844a(3) =4448444a(4) =444484444a(5) =44444844444External referencesoeis: A332148