Weight distributions found by digital computation are given for a number of Bose-Chaudhuri-Hocquenghem codes of length 2m_l for m as large as ten. The minimum weight was determined in some additional cases which include all non-trivial double, triple, and quadruple error correcting codes by theoretical results and by computer search. In each known case, the true minimum weight meets the Bose-Chaudhuri-Hocquenghem lower bound.nIt was observed that jaj = (n + 1 - j) a n+1-j for all BCH codesnfor which weights were computed, where n is the code length and a. the number of code words of weight j. It is shown that a BCH code extended by the addition of an overall parity check is invarient under permutations of the doubly-transitive affine group, and the observed equation holds as a consequence of this symmetry.
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