We ask users to provide proof(s), reference(s) to proof(s), or further clarification on the proof(s) in this space.
: ultraspherical/Gegenbauer polynomial : http://dlmf.nist.gov/18.3#T1.t1.r5
: ratio of a circle's circumference to its diameter : http://dlmf.nist.gov/5.19.E4
: Euler's gamma function : http://dlmf.nist.gov/5.2#E1
: Kronecker delta : http://dlmf.nist.gov/front/introduction#Sx4.p1.t1.r4
We ask users to provide relevant URL links in this space.