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.

A144422 a(n) = n!*A144416(n).

Original entry on oeis.org

1, 3, 62, 5052, 1087104, 487424520, 393702654960, 519740602925040, 1046019551260199040, 3046052768591313895680, 12322848899623787148556800, 67036205966744406283600262400, 477463744343745629221074425625600, 4354451197836949908463868034925593600
Offset: 0

Views

Author

David Applegate and N. J. A. Sloane, Dec 08 2008, corrected Jan 14 2009

Keywords

Comments

Number of placing of at least n objects but no more than 3*n distinct objects in n distinct boxes with the condition that in each box there is at least 1 object but no more than 3. - Adi Dani, May 04 2011

Crossrefs

Cf. A144416.

Programs

  • Mathematica
    t[n_, n_] = 1; t[n_ /; n >= 0, k_] /; 0 <= k <= 3*n := t[n, k] = t[n - 1, k - 1] + (k - 1)*t[n - 1, k - 2] + (1/2)*(k - 1)*(k - 2)*t[n - 1, k - 3]; t[, ] = 0; a[n_] := Sum[t[n, k], {k, 0, 3*n}]; Table[n!*a[n], {n, 0, 20}] (* Michael De Vlieger, Aug 04 2025, after Jean-François Alcover at A144416 *)