Arithmetic Sequence Calculator
Find the nth term and running sum of an arithmetic sequence.
Sequences that step evenly
An arithmetic sequence climbs or falls by the same amount each step, and its terms and sums follow tidy formulas. This tool finds the nth term and the total of the first n terms at once.
Starting at 2 with a common difference of 3 gives 2, 5, 8, 11 and so on; the tenth term is 29 and the first ten terms sum to 155. Change any input to explore the whole series.
Neat and private
It applies the sequence formulas in your browser, so nothing you enter is uploaded.
Frequently Asked Questions
What is an arithmetic sequence?
A list of numbers where each term increases by a fixed amount, the common difference, such as 2, 5, 8, 11.
What does it compute?
The nth term and the sum of the first n terms, plus a preview of the opening terms.
What are the formulas?
The nth term is the first term plus n minus one times the difference; the sum is n halves times the first plus the nth term.
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