a(n) = 4*(10^(2*n+1)-1)/9 + 2*10^n.A332146a(n) = 4*(10^(2*n+1)-1)/9 + 2*10^n.Terms a(0) =6a(1) =464a(2) =44644a(3) =4446444a(4) =444464444a(5) =44444644444External referencesoeis: A332146