A Simple Method for Determining Hadamard Sequency Vectors

Non-affine groups acting doubly transitively on a Hadamard matrix have been classified by Ito. Implicit in this work is a list of Hadamard matrices with non-affine doubly transitive automorphism group. We give this list explicitly, in the process ...

In 2013, Nebe and Villar gave a series of ternary self-dual codes of length $2(p+1)$ for a prime p congruent to 5 modulo 8. As a consequence, the third ternary extremal self-dual code of length 60 was found. We show that these ternary self-dual ...$\mathrm{}\mathrm{}$

It is proved that a code L(q) which is monomially equivalent to the Pless symmetry code C(q) of length $2q+2$ contains the (0,1)-incidence matrix of a Hadamard 3-$(2q+2,q+1,(q-1)/2)$ design D(q) associated with a Paley–Hadamard matrix of type II. ...$\mathrm{}\mathrm{}\mathrm{}\mathrm{}$${}^{}$${}^{}$