---
tag: 033WGN00BF
kind: concept
name: Formal power series
msc: [13F25]
sources:
  - url: https://en.wikipedia.org/wiki/Formal_power_series
    locator: Definition of the formal power series ring
same_as:
  wikidata: Q1003025
  wikipedia: Formal power series
---

## Summary

A formal power series is an infinite sum $\sum a_n X^n$ treated as an algebraic object, without any convergence condition. Formal power series form a ring that is the natural home of generating functions. The node [[formal power series|072W67KFYK]] gives the precise definition.