*N.B. A detailed on-line essay by S. Finch
was the starting point for this entry.*

A constant related to the Hard Square Entropy Constant. This constant is given by

(1) |

(2) |

(3) | |||

(4) | |||

(5) | |||

(6) | |||

(7) | |||

(8) | |||

(9) |

(Baxter 1980, Joyce 1988).

**References**

Baxter, R. J. ``Hard Hexagons: Exact Solution.'' *J. Physics A* **13**, 1023-1030, 1980.

Finch, S. ``Favorite Mathematical Constants.'' http://www.mathsoft.com/asolve/constant/square/square.html

Joyce, G. S. ``On the Hard Hexagon Model and the Theory of Modular Functions.'' *Phil. Trans. Royal Soc. London A* **325**, 643-702, 1988.

Plouffe, S. ``Hard Hexagons Constant.'' http://www.lacim.uqam.ca/piDATA/hardhex.html.

© 1996-9

1999-05-25