The binary extremal self-dual codes of lengths 38 and 40
We classify the extremal self-dual codes of lengths 38 or 40 having an automorphism of order 3 with six independent 3-cycles, 10 independent 3-cycles, or 12 independent 3-cycles. In this way we complete the classification of binary extremal self-dual codes of length up to 48 having automorphism of odd prime order.
self-dual code automorphism extremal code self-orthogonal code weight enumerator