%I #6 Apr 10 2013 17:09:40
%S 1,1,2,4,10,26,76,232,756,2548,8906,31846,116422,432758,1634944
%N Number of partial matchings of n elements treatable by "PTR" (Procedure Triple Reverse).
%H Lily Yen, <a href="http://arxiv.org/abs/1209.3082">A Bijection for Crossings and Nestings</a>, arXiv preprint arXiv:1209.3082, 2012
%K nonn
%O 1,3
%A _N. J. A. Sloane_, Dec 27 2012