The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A179062 Number of non-attacking placements of 7 rooks on an n X n board. 4
 0, 0, 0, 0, 0, 0, 5040, 322560, 6531840, 72576000, 548856000, 3161410560, 14841066240, 59364264960, 208702494000, 659602944000, 1906252508160, 5104345559040, 12796310741760, 30287126016000, 68146033536000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,7 LINKS Andrew Howroyd, Table of n, a(n) for n = 1..200 Christopher R. H. Hanusa, T Zaslavsky, S Chaiken, A q-Queens Problem. IV. Queens, Bishops, Nightriders (and Rooks), arXiv preprint arXiv:1609.00853, a12016 Index entries for linear recurrences with constant coefficients, signature (15,-105,455,-1365,3003,-5005,6435,-6435,5005,-3003,1365,-455,105,-15,1). FORMULA a(n) = 7!*binomial(n,7)^2. G.f.: -5040*x^7*(x+1)*(x^6+48*x^5+393*x^4+832*x^3+393*x^2+48*x+1) / (x-1)^15. - Colin Barker, Jan 08 2013 MATHEMATICA 7! Binomial[Range[30], 7]^2 (* or *) LinearRecurrence[{15, -105, 455, -1365, 3003, -5005, 6435, -6435, 5005, -3003, 1365, -455, 105, -15, 1}, {0, 0, 0, 0, 0, 0, 5040, 322560, 6531840, 72576000, 548856000, 3161410560, 14841066240, 59364264960, 208702494000}, 30] (* Harvey P. Dale, May 25 2017 *) PROG (PARI) a(n) = 7! * binomial(n, 7)^2 \\ Andrew Howroyd, Feb 13 2018 CROSSREFS Column k=7 of A144084. Cf. A179061 (6 rooks), A179063 (8 rooks). Sequence in context: A228910 A258419 A355023 * A342075 A055362 A246195 Adjacent sequences: A179059 A179060 A179061 * A179063 A179064 A179065 KEYWORD easy,nonn AUTHOR Thomas Zaslavsky, Jun 27 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 19 14:15 EDT 2024. Contains 372697 sequences. (Running on oeis4.)