-Fountains

An -fountain is an arrangement of coins in which each coin above the bottom row rests on two coins on the row below. For , the number of -fountains is .

SNAPSHOTS

  • [Snapshot]
  • [Snapshot]
  • [Snapshot]

DETAILS

An -fountain with coins in its base is sometimes called an -fountain. For a given , the widest fountain is just a bottom row of coins—an -fountain—and the tallest, narrowest fountain fills as much of a triangle as possible. Between the extremes, there are typically multiple -fountains.
References
[1] R. P. Stanley, Enumerative Combinatorics, Vol. 2, Cambridge: Cambridge University Press, 1999 p. 228.
[2] S. R. Finch, Mathematical Constants, Cambridge: Cambridge University Press, 2003 pp. 380–381.
[3] "A005169." The On-Line Encyclopedia of Integer Sequences. (Feb 15, 2012) oeis.org/A005169.
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.