1,2

This number is equivalent to the number of plans (i.e. structural solutions) of the open shop problem with n jobs and n machines - see problems in scheduling theory.

H. Braesel, M. Harborth, T. Tautenhahn and P. Willenius, On the set of solutions of the open shop problem, Ann. Oper. Res. 92 (1999) 241-263

M. Harborth, Structural analysis of shop scheduling problems, PhD thesis, Otto-von-Guericke-Univ. Magdeburg, GCA-Verlag, 1999 (in German)

Sequence in context: A147686 A048913 A104376 this_sequence A079176 A013754 A073940

Adjacent sequences: A053867 A053868 A053869 this_sequence A053871 A053872 A053873

nonn,nice,hard

Martin Harborth (Martin.Harborth(AT)vt.siemens.de)