A046167 Number of minimal covers on n objects with 6 members.

0, 0, 0, 0, 0, 1, 420, 100814, 18151560, 2723868147, 359750257020, 43199991728608, 4817721638970240, 506352103838393813, 50691406225311551700, 4872449650707855334482, 452435489306282260691640

Offset

1,7

Links

Indranil Ghosh, Table of n, a(n) for n = 1..100

Eric Weisstein's World of Mathematics, Minimal Cover.

Index entries for linear recurrences with constant coefficients, signature (420,-75586,7555800,-453096049,16299368820,-325685329164,2788484181840).

Formula

G.f.: x^6/[(1-57x)(1-58x)(1-59x)(1-60x)(1-61x)(1-62x)(1-63x)].

Mathematica

CoefficientList[Series[(x^6)/((1-57x)(1-58x)(1-59x)(1-60x)(1-61x)(1-62x)(1-63x)), {x, 0, 100}], x] (* Indranil Ghosh, Feb 20 2017 *)
CoefficientList[Series[x^6/Times@@(1-x*Range[57, 63]), {x, 0, 30}], x] (* or *) LinearRecurrence[{420, -75586, 7555800, -453096049, 16299368820, -325685329164, 2788484181840}, {0, 0, 0, 0, 0, 0, 1}, 30] (* Harvey P. Dale, Aug 06 2018 *)

Crossrefs

Cf. A035348.

Sequence in context: A035846 A223941 A360537 * A059951 A225992 A028683

Adjacent sequences: A046164 A046165 A046166 * A046168 A046169 A046170

Keyword

nonn,easy

Author

Eric W. Weisstein

Status

approved