A140639 - OEIS

%I #8 Jun 20 2017 23:08:35

%S 1,1,1,1,2,5,15,51,179,647,2397,9081,35181,139307,563218

%N Number of 4-noncrossing RNA structures with arc-length => 4.

%C Table 2, p. 30 of Han and Reidys. See diagrams p. 31. Combinatorial formulas and asymptotic results are also given.

%H Hillary S. W. Han, Christian M. Reidys, <a href="http://arxiv.org/abs/0803.1399">Pseudoknot RNA structures with arc-length => 4</a>

%Y Cf. A004148, A110319, A107905, A110320, A132441.

%K nonn

%O 1,5

%A _Jonathan Vos Post_, Jul 07 2008