Classification of extremal double circulant self-dual codes of lengths 64 to 72 (Q1381621)

Much work has been done towards classifying binary self-dual codes and finding extremal self-dual codes. Recently extremal double circulant self-dual codes have been classified for lengths \(n\leq 62\). In this paper, a complete classification of extremal double circulant self-dual codes of lengths 64 to 72 is presented. Almost all of the extremal double circulant singly-even codes given have weight enumerators for which extremal codes were not previously known to exist. The study provides a partial classification of all extremal self-dual codes of length upto 72.