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A104003
(3/4)*(27*n^2-137*n+180)*n^(n-6)*(2*n-6)!/(n-3)!.
1
6, 306, 29700, 4798080, 1178634240, 412483246560, 195891696000000, 121597736131872000, 95776583838282547200, 93456899248404570278400, 110767880742079885561036800, 156855803355661410000000000000, 261695274412151118929854464000000, 508262037307349207558239385902080000
OFFSET
4,1
REFERENCES
Lando S. K. and Zvonkine D., Counting ramified coverings and intersection theory on Hurwitz spaces I (cohomological identities). Moscow Mathematical Journal, vol. 7 (2007), no. 1, 85-107.
LINKS
D. Zvonkine, Home Page
MATHEMATICA
Table[3/(4(n-3)!) (27n^2-137n+180)(n^(n-6))(2n-6)!, {n, 4, 20}] (* Harvey P. Dale, Nov 01 2024 *)
PROG
(PARI) a(n)=(3/4)*(27*n^2-137*n+180)*n^(n-6)*(2*n-6)!/(n-3)! \\ Charles R Greathouse IV, May 01 2020
CROSSREFS
Sequence in context: A221850 A229148 A333482 * A280215 A015103 A282373
KEYWORD
nonn,easy,changed
AUTHOR
N. J. A. Sloane, Jan 30 2008
STATUS
approved