? is Gamma function, ki is natural number??k1+…+kn=j means arbitrary combination of ki add up and equal to j. How to program this in mathmetica language? Thank you!
It is not clear to me what the relation is between n and j, and whether k1,k2 etc can be zero. However you can get started by looking at how this is built:
g[j_, d_, n_] :=
Plus @@ Table[
Times @@ Map[Gamma[d + 2 #]/(#! Gamma[d/2]) &, k], {k,
IntegerPartitions[j, {n}]}]
Look up the key ingredient, which is IntegerPartitions
Thank you very much for your answer, Let me think about it based on your solution. And k1, k2…kn can be zero, there is no relation between n and j, but n can be set to 3 if needed.