I want to calculate above integral in Maple, the parameters $n_1,n_2,n_3$ are all natural numbers.
I execute the following command:
After I pressed enter the following error message appeared:
"Error, unable to match delimiters"
I'm new to Maple, could any one tell me what the problem here is and which would be the correct command? I think I can learn the commands for computing a range of integrals like this once I know the correct command for this integral.