What is an arithmetic sequence?

An arithmetic sequence is an ordered list of numbers where the difference between any two consecutive terms is always constant.

What is the common difference?

The common difference is the fixed number added to each term to get the next term in the sequence. It can be positive, negative, or zero.

Can I use negative numbers for the inputs?

Yes, both the first term and the common difference accept negative numbers, allowing you to calculate decreasing sequences.

What is the maximum term index I can calculate?

You can calculate up to the 100,000th term index using this tool.

How is the sum of terms calculated?

The tool uses the standard arithmetic series formula to compute the sum based on your provided first term, common difference, and number of terms.

Arithmetic Sequence Calculator | Online Free Tool

Examples

1. Checking Algebra Homework

Student

Background

A student is working on an algebra assignment and needs to find the 8th term and the sum of the first 8 terms of a sequence.

Problem

Manually calculating the sequence 3, 7, 11, 15... is time-consuming and prone to arithmetic errors.

How to use

Set the First Term to 3, Common Difference to 4, Term Index to 8, and Number Of Terms to 8.

{"firstTerm": 3, "commonDifference": 4, "termIndex": 8, "numberOfTerms": 8}

Outcome

The tool instantly outputs the 8th term as 31 and the sum of the first 8 terms as 136.

2. Calculating Auditorium Seating

Event Planner

Background

An event planner is organizing a venue where the first row has 20 seats, and each subsequent row adds 5 seats.

Problem

Need to quickly know how many seats are in the 15th row and the total capacity of the first 15 rows.

How to use

Input 20 as the First Term, 5 as the Common Difference, and 15 for both the Term Index and Number Of Terms.

{"firstTerm": 20, "commonDifference": 5, "termIndex": 15, "numberOfTerms": 15}

Arithmetic Sequence Calculator | Online Free Tool | Elysia Tools

Arithmetic Sequence Calculator

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Examples

1. Checking Algebra Homework

2. Calculating Auditorium Seating

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