Arithmetic sequence calculator
Find the nth term and the sum of the first n terms of an arithmetic sequence.
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Arithmetic sequence calculator: how it works
Practical information to understand the result and use this tool correctly.
About Arithmetic sequence calculator
Arithmetic sequences change by a constant difference d each step.
Closed forms give any term and the sum without listing every value.
Standard in algebra courses and financial arithmetic progressions.
How to use it
- 1Enter a₁, d, and n ≥ 1.
- 2Calculate aₙ and Sₙ.
- 3Negative d is allowed for decreasing sequences.
Frequently asked questions
- Is n 1-based?
- Yes — the first term is n=1.
- Sum formula?
- Sₙ = n/2 · (first + last) works too.