On a property of symmetric designs of order n\(\equiv 2(mod\,4)\)
In this paper the author gives a new proof of the following theorem. If S is a symmetric (v,k,\(\lambda)\) design of order \(n\equiv 2\) (mod 4), then \(v\equiv \pm 1\) (mod 8). This theorem was first proved by U. Ott as a consequence of general results concerning unimodular lattices associated with such a design. This new proof uses only the Bruck-Ryser-Chowla theorem and the identity \(v\lambda =k^ 2-n\).
scientific article; zbMATH DE number 4116545