A014627 Consider all complete bipartite graphs on 2n nodes and all possible assignment of weights w(i) (for nodes i=1,...,2n); sequence gives maximal number of ways to orient the edges of the graph so that each node i has w(i) edges oriented towards it (for i=1,...,2n).

1, 1, 2, 3, 6, 15, 90, 310, 1860, 8280, 163560, 1346940, 21476700

Offset

1,3

References

D. Z. Djokovic and J. Sanmiya, Three Identities for Symmetric Polynomials over Z/2Z, preprint, 1999.

Links

Table of n, a(n) for n=1..13.

Example

For n=2 the maximal bipartite graph has two nodes on each side and the weight of every node 1. The edges form a path which can be oriented forwards or backwards to give exactly one edge oriented towards each node. Thus for n=2 the sequence value is 2.

Crossrefs

Sequence in context: A214343 A007364 A305857 * A145781 A351880 A109162

Adjacent sequences: A014624 A014625 A014626 * A014628 A014629 A014630

Keyword

nonn

Author

Jason Scott Sanmiya (jssanmiy(AT)undergrad.math.uwaterloo.ca)

Status

approved