This article template uses the American Mathematical Society's amsart class. The sample is a short review of a result on computing eigenvectors from eigenvalues, with an abstract, introduction and a worked example, so it demonstrates how a maths paper is laid out. The same project also holds a homework template, an automatic homework version and a magazine class. The article runs to three pages.
Shared under the MIT License. All credit to nbwzx; the licence comes with the project's files.