
COMMENTS

It is conjectured by Kraeuter and Seifter that for n >= 5 the maximal permanent of a nonsingular n X n (+1,1)matrix is attained by a matrix with exactly n1 1's on the diagonal (compare A087981).
The maximal possible value for the permanent of a singular n X n (+1,1)matrix is obviously n!.


REFERENCES

A. R. Kraeuter and N. Seifter, Some properties of the permanent of (1,1)matrices, Linear and Multilinear Algebra 15 (1984), 207223.
N. Seifter, Upper bounds for permanents of (1,1)matrices, Israel J. Math. 48 (1984), 6978.
Edward TzuHsia Wang, On permanents of (1,1)matrices, Israel J. Math. 18 (1974), 353361.
