A permutation-based algorithm is introduced for the representation of closed RNA secondary structures. It is an efficient 'loopless' algorithm, which generates the permutations on base-pairs of 'k-noncrossing' setting partitions. The proposed algorithm reduces the computational complexity of known similar techniques in O(n), using minimal change ordering and transposing of not adjacent elements.
Keywords: Closed RNA secondary structures; k-noncrossing partitions; permutation-based algorithm.