a(n) is the largest n-digit cube.

Terms

a(0) =8a(1) =64a(2) =729a(3) =9261a(4) =97336a(5) =970299a(6) =9938375a(7) =99897344a(8) =997002999a(9) =9993948264a(10) =99961946721a(11) =999700029999