Hi all, I have been interested in La Jolla covering tables lately and I was wondering if there is some theory around sets where the same element is allowed to be present more than once. For example the following block would be considered valid: {1, 1, 1, 2, 3}. Basically given an alphabet {A, B, C, D} and given a word length (k), find the minimum set of words which cover the whole language with a max of N "letter replacements". For example, if the alphabet is binary {0,1} and word length is 3, a set covering "-1" would be { 000, 111} since all other words differ for at most by one char.

P.S. I would also be interested in the algorithms used to generate the tables itself, by I cannot find pointers. Thanks