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.

A284287 Number of possible legal open chains of a set of dominoes tiles with 0 to 2n pips.

Original entry on oeis.org

12, 126720, 7959229931520, 10752728122249860612096000, 829276462388385539562198269952000000000000, 7969891788752886799729592752113502210704733844275200000000000000, 18306383771271364475276585375748692499524930312437317320546133915243380736000000000000000000
Offset: 1

Views

Author

Amiram Eldar, Mar 24 2017

Keywords

Comments

a(3) corresponds to the standard double-six set of 28 tiles. The question for its value was asked by Louis Poinsot in 1809 and by Orly Terquem in 1849 and was first calculated by Michel Reiss in 1859 (published in 1871).
The problem of finding a(2) appears in Henry Dudeney's book.
a(4) was calculated by Gaston Tarry in 1886.
The number of legally closed chains is a(n)/((n+1)*(2n+1)) = n^(2n+1) * A135388(n) (i.e., divided by the number of tiles in the set, A000217(2n+1)) = 2, 8448, 284258211840, 238949513827774680268800, ... .
If reverse order is not counted, the number of open chains is a(n)/2 = 6, 63360, 3979614965760, 5376364061124930306048000, ..., and the number of closed chains is a(n)/(2*(n+1)*(2n+1)) = 1, 4224, 142129105920, 119474756913887340134400, ... .

Examples

			For n=1 there is 1 basic chain of 6 tiles: (0|0)(0|1)(1|1)(1|2)(2|2)(2|0). There are 6 cyclic permutations and a 2nd version for each, in a reverse order, so a(1) = 1 * 6 * 2 = 12.
		

References

  • Henry Ernest Dudeney, "The Fifteen Dominoes", Amusements in Mathematics, Nelson, Edinburgh 1917, pp. 209-210.
  • Martin Gardner, Mathematical Circus, Alfred A. Knopf, NY, 1979, pp. 137-142.
  • Donald E. Knuth, The Art of Computer Programming, Volume 4A, Addison-Wesley, 2011, pp. 389 and 745.
  • K. W. H. Leeflang, Domino games and domino puzzles, St. Martin's Press, New York, 1975, Chapter VIII, section 1, pp. 125-134.
  • Édouard Lucas, "La géométrie des réseaux et le problème des dominos", Récréations mathématiques, Volume 4, Gauthier-Villars, Paris, 1894, pp. 125-129.
  • Yakov Perelman, Figures for Fun, Foreign Languages Publishing House, Moscow, 1957, p. 38.
  • Miodrag S. Petković, "Poinsot's Diagram-tracing Puzzle", Famous Puzzles of Great Mathematicians, Amer. Math. Soc. (AMS), Providence RI, 2009, pp. 245-247
  • Michel Reiss, Evaluation du nombre de combinaisons desquelles les 28 dés d'un jeu du Domino sont susceptibles d'après la règle de ce jeu, Annali di Matematica Pura ed Applicata, Vol. 5.1 (1871), pp. 63-120.
  • W. W. Rouse Ball and H. S. M. Coxeter, Mathematical Recreations and Essays, Dover NY, 1987, pp. 243-254.

Crossrefs

Formula

a(n) = (n+1)*(2n+1)*n^(2n+1)*A135388(n) = (n+1)*(2n+1)*n^(2n+1)*(n-1)!^(2n+1)*A007082(n).