Optimal self-dual codes over Z4

The optimal minimal Euclidean norm of self-dual codes over ℤ_4 is known through length 24; the purpose of the present note is to determine the optimal minimal Hamming and Lee weights in this range. In the process, we classify all Lee-optimal codes of length 18, 21, 23, and 24. In particular, we find a total of 13 inequivalent codes with the same symmetrized weight enumerator as the Hensel-lifted Golay code.

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