A054583 - OEIS

A054583

Number of nonisomorphic acyclic orientations of the Hamming graph (K_n) x (K_n).

1, 3, 280, 6028059

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Also number of plans (i.e., structural solutions) of the open shop problem with n jobs and n machines where the jobs may be interchanged with the machines - see problems in scheduling theory.

REFERENCES

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

LINKS

Table of n, a(n) for n=1..4.

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

CROSSREFS

Cf. A053870.

Sequence in context: A096126 A057599 A239273 * A139984 A057631 A058455

Adjacent sequences: A054580 A054581 A054582 * A054584 A054585 A054586

KEYWORD

nonn,nice,hard,more

AUTHOR

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

STATUS

approved