Largest square <= 10^n.

Terms

a(0) =9a(1) =100a(2) =961a(3) =10000a(4) =99856a(5) =1000000a(6) =9998244a(7) =100000000a(8) =999950884a(9) =10000000000a(10) =99999515529a(11) =1000000000000