I'm studying mechanical engineering, just have a question on the labyrinth seal leakage equation. More specifically, the expansion ratio formula. What does the '1n' stand for? With 'n + 1n', I'm assuming those two n's are different since one looks like it's in italics and the other looks normal. Can someone please clear this up for me? I understand the rest of the equation, I just can't find what '1n' stands for in my textbook.