A generating function is a formal power series where the coefficient at $x^n$ usually counts the number of combinatorial objects of size $n$.

Sometimes the coefficients are normalized, as is the case with exponential generating functions, where the $n$^th coefficient is divided by $n!$. This can give the operations on the series a different meaning.

Problems

• Bus Routes
• The Child and Binary Tree
• Devu and Locks
• Devu and Birthday Celebration
• Tricolored Coin Fountains

See also

• Formal power series