A138896 Ratio of (2n-1)! to number of zeros in Sylvester matrix of polynomial of n degree with all nonzero coefficients.

3, 15, 280, 11340, 798336, 86486400, 13343616000, 2778808032000, 750895681536000, 255454710858547200, 106826515449937920000, 53858368206010368000000, 32215590089995124736000000

Offset

2,1

Comments

(2n-1)! = A009445 = number of monomials in determinant of symbolic square matrix of size 2n-1 X 2n-1 without zeros.

Links

Table of n, a(n) for n=2..14.

Formula

a(n)=(2 n - 1)!/(2 (n - 1)^2) (n=2,3,4,...)

Mathematica

Table[(2 n - 1)!/(2 (n - 1)^2), {n, 2, 20}]

Crossrefs

Cf. A001105, A009445, A007878.

Sequence in context: A013353 A270401 A270001 * A090627 A070234 A036279

Adjacent sequences: A138893 A138894 A138895 * A138897 A138898 A138899

Keyword

nonn

Author

Artur Jasinski, Apr 02 2008

Status

approved