*The notation <math>^n a</math> means <math>a^{a}^{\dots}^{a}^</math> the application of exponentiation <math> n-1</math> times. | *The notation <math>^n a</math> means <math>a^{a}^{\dots}^{a}^</math> the application of exponentiation <math> n-1</math> times. |