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 A138896 Ratio of (2n-1)! to number of zeros in Sylvester matrix of polynomial of n degree with all nonzero coefficients. 2
 3, 15, 280, 11340, 798336, 86486400, 13343616000, 2778808032000, 750895681536000, 255454710858547200, 106826515449937920000, 53858368206010368000000, 32215590089995124736000000 (list; graph; refs; listen; history; text; internal format)
 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 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

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Last modified January 19 17:45 EST 2019. Contains 319309 sequences. (Running on oeis4.)