A364777 a(n) = (n^2)!*(n!)^2/(2*n-1)!.

1, 16, 108864, 2391175987200, 615524208068689920000000, 4831082166102613213870122703257600000000, 2481336275198061145749280386508780674949224836628480000000000

Offset

1,2

Comments

a(n) is the number of square matrices of size n, whose elements are a permutation of 1, 2, ..., n^2, having a saddle point.

Links

Table of n, a(n) for n=1..7.

A. J. Goldman, The probability of a saddlepoint, The American Mathematical Monthly, 64, 10 (1957), pp. 729-730.

E. D. Thorp, The probability that a matrix has a saddle point, Information Sciences 19 2 (1979), 91-95.

Crossrefs

Sequence in context: A144830 A278289 A298202 * A332090 A333863 A343245

Adjacent sequences: A364774 A364775 A364776 * A364778 A364779 A364780

Keyword

nonn

Author

Sela Fried, Aug 07 2023

Status

approved