Arithmetic growth
First 3, difference 4, 5 terms3, 7, 11, 15, 19
Number Sequence Calculator
Use this free number sequence calculator to generate arithmetic sequences, geometric sequences, Fibonacci-style sequences, formulas, next terms, steps, copy, and recent tab history.
Inputs to checkExample numbersCopyable answerTab-only history
a(n) = 3 + (n - 1) x 43, 7, 11, 15, 19, 23, 27, 31
- Type
- arithmetic
- Next terms
- 35, 39, 43
- Terms
- 8
Steps
- Start with first term 3.
- Add the common difference 4 each time.
- Generate 8 terms, then continue the same pattern for the next terms.
Recent answers
Recent answers will appear here.
Input tips
Arithmetic sequences add a constant difference.
Geometric sequences multiply by a constant ratio.
Fibonacci-style sequences start with two terms and add the previous two.
Terms to show must be a whole number from 2 to 30.
How to use the Number Sequence Calculator
- Choose arithmetic, geometric, or Fibonacci sequence mode.
- Enter the starting values and how many terms you want.
- Press Generate sequence to see the list, rule, and next term.
- Use examples, recent answers, or copy the sequence while studying patterns.
What people use it for
Create an arithmetic sequence from a first term and common difference.
Create a geometric sequence from a first term and common ratio.
Generate a Fibonacci-style sequence from two starting terms.
Check the visible formula before copying a sequence into homework notes.
Preview the next three terms after the list you asked to show.
Test decimals, negative differences, fractional ratios, and decreasing patterns.
Quick examples
Arithmetic decrease
First 20, difference -3, 6 terms20, 17, 14, 11, 8, 5
Geometric growth
First 2, ratio 3, 5 terms2, 6, 18, 54, 162
Geometric half-life style
First 64, ratio 0.5, 6 terms64, 32, 16, 8, 4, 2
Classic Fibonacci-style
Start 1 and 1, 7 terms1, 1, 2, 3, 5, 8, 13
Custom Fibonacci-style
Start 2 and 5, 7 terms2, 5, 7, 12, 19, 31, 50
Need the guide or a nearby tool?
Need a slower walkthrough, a related calculator, or the full library? These links keep you close to the task you started.
- How to use the Number Sequence CalculatorSee slower examples, input meanings, formula notes, result limits, and mistakes to avoid.
- CalculatorsBrowse related calculators and utilities in the same category.
- Calculator and utility guidesFind more guides that use real tool inputs and example numbers.
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Frequently asked questions
Quick answers about formulas, inputs, examples, result copying, and private in-browser history.
What sequence types are supported?
The calculator supports arithmetic, geometric, and Fibonacci-style sequences. Choose the mode first so the second input means the right thing for that rule.
What is an arithmetic sequence?
An arithmetic sequence changes by adding the same amount each time. The calculator uses a(n) = first + (n - 1) x difference.
What do the main Number Sequence Calculator inputs mean?
The main inputs are the numbers, operation, mode, or known values the calculator needs. Keep units consistent, enter percentages the way the page label shows, and use the examples as a quick check before trusting the answer.
How should I read the Number Sequence Calculator answer?
Read the headline answer, then check the supporting lines and examples to understand how the calculator got there. If one input changes, rerun the tool and compare the new answer instead of guessing.
What should I double-check before trusting the Number Sequence Calculator?
Check units, signs, rounding, and the selected mode before copying the answer. If the number feels weird, rerun one of the examples first, then put your own values back in slowly.
What is a geometric sequence?
A geometric sequence changes by multiplying by the same value each time. The calculator uses a(n) = first x ratio^(n - 1).
How does the Fibonacci-style mode work?
Fibonacci-style mode starts with two values, then adds the previous two terms to make each next term. Starting with 2 and 5 gives 2, 5, 7, 12, 19, and so on.
What does the second field mean?
In arithmetic mode it is the common difference. In geometric mode it is the common ratio. In Fibonacci-style mode it is the second starting term.
How many terms can I generate?
Terms to show must be a whole number from 2 to 30. The result also shows the next three terms after the displayed list.
Can I generate decimals or negative terms?
Yes. The first term, common difference, common ratio, and second Fibonacci-style term can be decimals or negative numbers, as long as the values stay finite.
What is the difference between common difference and common ratio?
A common difference is added each time, such as +4. A common ratio is multiplied each time, such as x3 or x0.5.
Why can geometric sequences get large so quickly?
Geometric sequences multiply by the ratio every step, so ratios larger than 1 can grow fast. Use fewer terms or a smaller ratio if the output becomes too large to read.
Can this identify an unknown pattern from a pasted list?
No. This page generates sequences from the rule you choose. It does not infer arbitrary patterns from an existing list of numbers.
What do next terms mean?
Next terms are the three values that would follow after the number of terms you asked to show, using the same rule.
Is my sequence history private?
Yes. Recent sequences stay only in the current browser tab while you use the page. They are not sent to a server.