TRINUCLEOTIDE CIRCULAR CODES

For any positive integer n we introduce the property µn that holds for a set X of n self-complementary couples of trinucleotides (called in this paper “forbidden configuration”) when, for all m < n, all the sets of m self-complementary couples of trinucleotides contained in X are circular codes but X itself is not a circular code. We prove that each forbidden configuration contains at most 4 self-complementary couples of trinucleotides, i.e. the maximum integer such that the property µn holds is 4. Mathematics Subject Classification (2010). 94A45. Key words: trinucleotide circular codes; self-complementary trinucleotide circular codes; neck-lace. 3