A hook length formula is a formula for the number of Young tableaux associated with a given Ferrers
diagram. In each box, write the sum of one plus the number of boxes horizontally
to the right and vertically below the box (the "hook length"). The number
of tableaux is then 
divided by the product of all "hook lengths."
Hook Length Formula
See also
Ferrers Diagram, Young TableauExplore with Wolfram|Alpha
References
Jones, V. "Hecke Algebra Representations of Braid Groups and Link Polynomials." Ann. Math. 126, 335-388, 1987.Skiena, S. Implementing Discrete Mathematics: Combinatorics and Graph Theory with Mathematica. Reading, MA: Addison-Wesley, 1990.Referenced on Wolfram|Alpha
Hook Length FormulaCite this as:
Weisstein, Eric W. "Hook Length Formula." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/HookLengthFormula.html