How it works
aₙ=a₁+(n−1)d; Sₙ=n(a₁+aₙ)/2.
Input definitions
- First term a₁
- Enter the value in the labeled unit.
- Common difference
- Enter the value in the labeled unit.
- Term number n
- Enter the value in the labeled unit.
A worked example
- First term a₁
- 3
- Common difference
- 4
- Term number n
- 10
39
Assumptions & limits
Mathematical calculation using the stated inputs; not a measurement guarantee.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-17. Content checked against the stated method and examples. Our verification approach.
Common questions
Why can statistical results differ between tools?
Denominator, interpolation and boundary conventions can differ. Use the method and assumptions on this page to compare the same definition; displayed decimals may also be rounded.
How does the Arithmetic sequence and sum tool work?
aₙ=a₁+(n−1)d; Sₙ=n(a₁+aₙ)/2.
What are the assumptions and limits of Arithmetic sequence and sum?
Mathematical calculation using the stated inputs; not a measurement guarantee.