a(n) = 5*(10^(2*n+1)-1)/9 - 3*10^n.A332152a(n) = 5*(10^(2*n+1)-1)/9 - 3*10^n.Terms a(0) =2a(1) =525a(2) =55255a(3) =5552555a(4) =555525555a(5) =55555255555External referencesoeis: A332152