Triangle Coefficient

Author

Eric W. Weisstein
February 12, 2004

This notebook downloaded from http://mathworld.wolfram.com/notebooks/SpecialFunctions/TriangleCoefficient.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/TriangleCoefficient.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

Definition

Δ[a_,b_,c_]:=(((a+b-c)! (a-b+c)! (-a+b+c)!)/((1+a+b+c)!))

Factorial/@Times@@Plus@@@Thread[(Table[1,{3},{3}]-2IdentityMatrix[3]){a,b,c}]/(a+b+c+1)!