Self-dual codes based on the twin prime product 35

Abstract

A (70,35) circulant code was previously characterized in terms of the incidence matrix of a Hadamard difference set based on the twin prime product 35. The weight distribution of this code is computed. The (70,35) d=11 code is extended to a (72,36) d=12 self-dual code which is not equivalent to the extended quadratic residue code. A (70,35) d=10 self dual code is also described in terms of a (35,17,8) cyclic difference set.