A226510 Number of extended RNA secondary structures of size n according to the zu Siederdissen et al. (2011) model.

1, 1, 2, 6, 20, 66, 221, 757, 2647, 9402, 33813, 122876, 450543, 1664835, 6193553, 23178525, 87199503, 329592705, 1251029482, 4766563155, 18223733493, 69892469057, 268824143700, 1036690445777, 4007586822784

Offset

1,3

Comments

It appears that "pseudoknot-free RNA secondary structures with base triples are a new combinatorial object and ... not bijective to any other combinatorial objects studied before". [Müller and Nebel]

Links

Table of n, a(n) for n=1..25.

Christian Höner zu Siederdissen, Stephan H. Bernhart, Peter F. Stadler, Ivo L. Hofacker, A folding algorithm for extended RNA secondary structures, Bioinformatics, 27(13):129-136 (2011).

R. Müller and M. E. Nebel, Combinatorics of RNA secondary structures with base triples, preprint of Journal of Computational Biology, Jul 2015.619-648, 2013.

Crossrefs

Sequence in context: A111285 A052991 A246019 * A108627 A193234 A285197

Adjacent sequences: A226507 A226508 A226509 * A226511 A226512 A226513

Keyword

nonn

Author

N. J. A. Sloane, Jun 11 2013

Status

approved