With the exception of some pairs of groups of orders 4 and 6, which are listed explicitly, different group tables of order n differ in at least 2n places; and with the exception of some pairs of groups of orders 4, 6, 8 and 9, which are listed explicitly, tables of non-isomorphic groups of order n always differ in strictly more than 2n places.
(1991 Mathematics Subject Classification: 05B15, 20N05, 20A99.)
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