A134164 a(n) = 8*(6*n^2-37*n+60)*n^(n-7)*(2*n-7)!/(n-4)!.

1, 48, 4320, 638400, 143216640, 45912303360, 20064844800000, 11517786190310400, 8429182295998464000, 7676025035655591014400, 8524944488872455752908800, 11353372433362159200000000000, 17873609218353722680651284480000, 32855463684946243953215776972800000, 69770867798960701944675685147607040000

Offset

4,2

Links

G. C. Greubel, Table of n, a(n) for n = 4..100

S. K. Lando and D. Zvonkine, Counting ramified coverings and intersection theory on Hurwitz spaces I (cohomological identities), Moscow Mathematical Journal, vol. 7 (2007), no. 1, 85-107.

D. Zvonkine, Counting ramified coverings and intersection theory on Hurwitz spaces II (local structure of Hurwitz spaces and combinatorial results), Moscow Mathematical Journal, vol. 7 (2007), no. 1, 135-162.

D. Zvonkine, Home Page

Mathematica

Table[ 8*(6*n^2 - 37*n + 60)*n^(n - 7)*(2*n - 7)!/(n - 4)!, {n, 4, 50}] (* G. C. Greubel, May 30 2016 *)

Crossrefs

Sequence in context: A033475 A053060 A004034 * A270253 A098209 A208793

Adjacent sequences: A134161 A134162 A134163 * A134165 A134166 A134167

Keyword

nonn

Author

N. J. A. Sloane, Jan 30 2008

Status

approved