|
%I #9 Jan 08 2018 01:47:43
%S 1,3,19,195,2791,51423,1167979,32067675,1064281951,43806954183,
%T 2376985075939,186194963282595,22598045194449271,4259417828951807343,
%U 1200382884654622348699,490727012583769876310955,286998078380075662131967951,238889878466868543045084230103
%N Number of labeled semitransitive orders on n elements: (1+3)-free posets.
%H M. Guay-Paquet, A. H. Morales, E. Rowland, <a href="http://arxiv.org/abs/1212.5356">Structure and enumeration of (3+1)-free posets (extended abstract)</a>, arXiv:1212.5356 [math.CO], 2012.
%F E.g.f.: S(e^x-1, T(x)), where S(x, y) is the g.f. for A221494 and T(x) is the e.g.f. for A221493. [_Mathieu Guay-Paquet_, Jan 18 2013]
%Y Cf. A079146 (unlabeled semitransitive orders).
%K nonn,easy
%O 1,2
%A Detlef Pauly (dettodet(AT)yahoo.de), Dec 27 2002
%E More terms from _Mathieu Guay-Paquet_, Jan 18 2013
|
