ECONOMISTS CLAIM to study markets in all their forms. But one, in particular, seems to make them blush: sex work. In a new book, “Sex Work by Numbers”, Stef Adriaenssens of KU Leuven, a university in ...

Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child ...

Jim Dolan and I are trying to learn about modular forms and the Modularity Theorem, once known as the Taniyama–Shimura–Weil Conjecture. It’s an irresistible challenge. After all, this result implies ...