In this novel "there's "mathematicians' graffiti" and a lot of musing on the Poisson-curve. See, for ex. page 140 in the Pengiun 20th century classics edition.

I was impressed with Pynchon's reference to mathematics (particularly statistics, in the beginning, w/ Ned Pointsman and Roger Mexico and calculus when talking about the guidance systems, brennschluss, and the rocket's path being calculable as an integration over time), which were not overbearing or forced, but rather enlightening, almost poetic. It's rare to find a major author of fiction who can write in a modality where mathematics is really a tool for understanding cause and effect. Without being elitist, I think that Pynchon's fluent use of math is one reason that many students of literature find this book is hard to approach; if the classic Victorian novel frames the world as a matrix of social interactions reduceable to sometimes hidden motivations, Gravity's Rainbow at times frames the world as a set of physical interactions reduceable to mathematical relationships. Math in this book is pervasive, and a reader of the work who is familiar with integral calculus will be able to pick up on analogies that I can easily see being lost on the uninitiate.

May I just add, the integral of one over cabin(d)cabin = log(cabin)+c = houseboat, a marvelous pun that illustrates perfectly Pynchon's use of mathematics in his fiction, not centrally but as another way of getting toward a greater idea or theme.