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

Author

Eric W. Weisstein

Keywords

• nonn
• easy

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).

Crossrefs

Cf. A035348.

Programs

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 *)

Formula

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