MATH GIRLS is a YA novel, both teen romance & intro to higher mathematics; "like Glee for math nerds" said one reviewer. It's been translated from the Japanese by Bento Books.
It starts with a lonely female freshman on her first day of high school. Her escape is advanced mathematics. She tunes out the principal and starts think about her age as factorals (15 = 3x5, 16=2^4, 17 is a prime number). And then, she meets Miruka. And Tetra.
The math is good and the book covers a wide variety of topics in mathematics, from basics like how letters are assigned as variable names to quite challenging problems like finding a general term for the sequence of integer partition numbers.
Judge for yourself. The first two chapters available as a sample. Download the sample PDF here: Math Girls Chapters 1 & 2
