What is the author's style in Pnin by Vladimir Nabokov?

The book is divided into seven different chapters. The first six are of approximately equal length; the seventh is by far the shortest in the book, about half the size—eighteen pages—of some of the other, larger chapters. Each chapter is divided into different numbered sections which neatly divide the chapter into different episodes. The book seems to straddle the line between being a collection of connected short stories and a novel. There is certainly overlap between the chapters, but it is difficult to identify any overarching plot.