%I A054652
%S A054652 1,2,14,204,5016,185520,9595440,659846880,58130513280,6376568728320,
%T A054652 851542303852800,135930981520857600,25547289000870067200,
%U A054652 5581430113409537587200,1402137089367777207244800
%N A054652 Acyclic orientations of the Hamming graph (K_2) x (K_n).
%C A054652 This number is equivalent to the number of plans (i.e. structural solutions) 
               of the open shop problem with n jobs and 2 machines - see problems 
               in scheduling theory.
%D A054652 H. Braesel, M. Kleinau, On the number of feasible schedules of the open 
               shop problem - an application of special Latin rectangles, Optimization 
               23 (1992) 251-260
%D A054652 M. Harborth, Structural analysis of shop scheduling problems, PhD thesis, 
               Otto-von-Guericke-Univ. Magdeburg, GCA-Verlag, 1999 (in German)
%H A054652 <a href="http://www.math.uni-magdeburg.de/publ/diss/sources/harborth_diss.ps.gz">
               Structural analysis of shop scheduling problems (PhD thesis in German 
               with English abstract)</a>
%F A054652 n!*Sum[n!/k!*binomial[n, k], {k, 0, n}]
%t A054652 Table[n!*Sum[n!/k!*Binomial[n, k], {k, 0, n}], {n, 0, 20}]
%Y A054652 A002720*n! Cf. A054653, A053870, A054583.
%Y A054652 Sequence in context: A090300 A102224 A123543 this_sequence A122647 A158097 
               A136550
%Y A054652 Adjacent sequences: A054649 A054650 A054651 this_sequence A054653 A054654 
               A054655
%K A054652 nonn,easy
%O A054652 0,2
%A A054652 M. Harborth (Martin.Harborth(AT)vt.siemens.de)