Subject: question for the list From: Allen Hatcher Date: Fri, 24 Sep 2004 14:19:58 -0400 To: Don Davis Does anyone know a reference to quote for the formula for the Euler characteristic of the Grassmann manifold of k-planes in n-space, in particular for the case k = 2 ? Remarks: A cell structure is given in Milnor-Stasheff, with a description of the number of cells in each dimension in terms of partitions, so it's just a combinatorial question, rather simple for k = 2. But I don't remember seeing a formula in the literature. Allen Hatcher