Largest n-digit triangular number.

Terms

a(0) =6a(1) =91a(2) =990a(3) =9870a(4) =99681a(5) =998991a(6) =9997156a(7) =99991011a(8) =999961560a(9) =9999878910a(10) =99999957291a(11) =999999911791