A134175 a(n) = (32/2)*(n-1)*(n-2)*(n-3)*(n-4).

0, 0, 0, 0, 384, 1920, 5760, 13440, 26880, 48384, 80640, 126720, 190080, 274560, 384384, 524160, 698880, 913920, 1175040, 1488384, 1860480, 2298240, 2808960, 3400320, 4080384, 4857600, 5740800, 6739200, 7862400, 9120384, 10523520, 12082560, 13808640, 15713280

Offset: 1

Author

N. J. A. Sloane, Jan 30 2008

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000
• D. Zvonkine, Home Page
• 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.
• Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Crossrefs

Cf. A052762.

Programs

Mathematica

LinearRecurrence[{5, -10, 10, -5, 1}, {0, 0, 0, 0, 384} , 50] (* or *) Table[(32/2)*(n-1)*(n-2)*(n-3)*(n-4), {n,1,50}] (* G. C. Greubel, May 30 2016 *)

PARI

a(n) = 16*(n-1)*(n-2)*(n-3)*(n-4) \\ Michel Marcus, Jun 27 2013

Formula

G.f.: 384*x^5/(1-x)^5. - Colin Barker, Aug 28 2012