cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A019579 Place n distinguishable balls in n boxes (in n^n ways); let f(n,k) = number of ways that max in any box is k, for 1 <= k <= n; sequence gives f(n,n-2)/n.

Original entry on oeis.org

2, 45, 160, 375, 756, 1372, 2304, 3645, 5500, 7986, 11232, 15379, 20580, 27000, 34816, 44217, 55404, 68590, 84000, 101871, 122452, 146004, 172800, 203125, 237276, 275562, 318304, 365835, 418500, 476656, 540672, 610929, 687820, 771750, 863136, 962407
Offset: 3

Views

Author

Lee Corbin (lcorbin(AT)tsoft.com), N. J. A. Sloane

Keywords

Crossrefs

Cf. A019576.

Programs

  • Mathematica
    CoefficientList[Series[-(9 x^6 - 35 x^5 + 41 x^4 + 5 x^3 - 45 x^2 + 35 x + 2)/(x - 1)^5, {x, 0, 50}], x] (* Vincenzo Librandi, Oct 16 2013 *)
    LinearRecurrence[{5,-10,10,-5,1},{2,45,160,375,756,1372,2304},40] (* Harvey P. Dale, Dec 18 2020 *)

Formula

a(n) = n*(n-1)^3/2, n >= 5.
G.f.: -x^3*(9*x^6 - 35*x^5 + 41*x^4 + 5*x^3 - 45*x^2 + 35*x + 2) / (x-1)^5. [Colin Barker, Jan 11 2013]
a(n) = 5*a(n-1)-10*a(n-2)+10*a(n-3)-5*a(n-4)+a(n-5). - Wesley Ivan Hurt, Dec 27 2021

Extensions

More terms from Vincenzo Librandi, Oct 16 2013