Telescoping Series Calculator

Enter a telescoping series of the form 1/(n*(n+k)) to see partial fractions, term-by-term cancellation, and the exact partial and infinite sums.

Use the Telescoping Series Calculator

Series Parameters

Series

∑ 1 / (n × (n + 1))

Series: ∑ 1/(n×(n+k))

Between 2 and 20

Summary

Enter a telescoping series of the form 1/(n*(n+k)) to see partial fractions, term-by-term cancellation, and the exact partial and infinite sums.

How it works

  1. Enter the gap k (the spacing between factors) for the series sum 1/(n*(n+k)).
  2. Choose a positive starting index and the number of terms to display.
  3. The tool applies partial fraction decomposition: 1/(n*(n+k)) = (1/k)*(1/n - 1/(n+k)).
  4. Terms are expanded row by row so you can watch intermediate fractions cancel.
  5. The partial sum and S(∞) = (1/k) × sum from m=start through start+k−1 of 1/m are displayed.

Use cases

  • Check homework answers for telescoping series problems.
  • Visualize why telescoping series converge to a clean closed form.
  • Verify partial fraction decomposition by expanding the series.
  • Explore how changing k shifts the cancellation pattern.
  • Use as a teaching aid to demonstrate series collapsing.
  • Quickly compute partial sums without manual arithmetic.

Frequently Asked Questions

Last updated: 2026-09-26 · Reviewed by Nham Vu