Exercise 3.
Show how you can get the generating function for the triangular numbers in three different ways:
Take two derivatives of the generating function for \(1,1,1,1,1, \ldots\)
Use differencing.
Multiply two known generating functions.
Show how you can get the generating function for the triangular numbers in three different ways:
Take two derivatives of the generating function for \(1,1,1,1,1, \ldots\)
Use differencing.
Multiply two known generating functions.