A132441 Number of 3-noncrossing stack-free partial matchings without 1-arcs.

1, 1, 2, 5, 12, 31, 88, 263, 814, 2604, 8575, 28936, 99726, 350151, 1249865

Offset: 1

Author

Emma. Y. Jin (emma(AT)cfc.nankai.edu.cn), Nov 13 2007

Keywords

• nonn

References

• Emma Y. Jin and Christian M. Reidys. RNA-Lego: Combinatorial design of pseudoknot RNA, Bull. Math. Bio. 2007, submit

Links

• Emma Y. Jin and Christian M. Reidys, RNA-LEGO: Combinatorial Design of Pseudoknot RNA, arXiv:0711.1405 [q-bio.BM], 2007.

Formula

C_k(n,h) = Sum_{b=0..h-1} (-1)^(h-b-1)*(binomial(h-1, b)*{T}_k(h-2h+2b+2,b+1).