Math Calculators

Number Sequence Calculator

Use this number sequence calculator to solve a math task around number sequence with visible inputs, formula notes, and a reusable example.

Primary answer
Generated terms
Inputs to verify
Sequence type, First term, and Common difference or ratio
Use type
Use as a direct calculation check.
Keyword intent
number sequence calculator

Calculator

Number Sequence Calculator

Calculates generated terms from sequence type, first term, common difference or ratio. Defaults are filled in so you can review a working example before changing inputs.

Choose arithmetic for a common difference or geometric for a common ratio.

The first term is a1.

In arithmetic mode this is d; in geometric mode this is r.

Generate between 1 and 100 terms.

Indexing starts at n = 1.

Result

Result reflects the current submitted inputs.

  • Risk A
  • Reviewed 2026-05-26
  • 2 sources
Generated terms2, 5, 8, 11, 14
Target term29
Sum of generated terms40
Formulaa_n = a_1 + d(n - 1)

Breakdown

Sequence type
arithmetic
Common difference
3
  • Indexing starts at n = 1.
  • The step value is a common difference in arithmetic mode and a common ratio in geometric mode.
  • The calculator generates terms from a known formula; it does not infer formulas from arbitrary lists.
  • Raw numeric outputs are rounded to 10 decimal places for stable display.

Accuracy notes

Risk level
A
Reviewed
2026-05-26
Sources
2
Primary result
Generated terms

Formula logic is kept in a pure calculator module with fixtures, source notes, and page-visible assumptions.

What the result means

Generated terms is the number to carry forward from this number sequence calculation. The first requested terms in the sequence. Use the primary result for the number sequence task, then check the secondary outputs for context. Use target term, sum of generated terms, and formula to explain why generated terms moved when an input changed. Copy the result only after the inputs, assumptions, and source notes match your case. Check unit handling, rounding, included inputs, excluded inputs, and source version before treating the result as final.

Generated termsThe first requested terms in the sequence.
Target termDisplayed as decimal.
Sum of generated termsDisplayed as decimal.
FormulaDisplayed as text.

Use the result this way

  1. Start with Generated terms, then use supporting outputs only to explain the primary answer.
  2. Verify sequence type, first term, and common difference or ratio before copying the result.
  3. Choose the mode or method first because it can change which formula is applied and stay within the documented minimum and maximum ranges.
  4. Copy the result only after the inputs, assumptions, and source notes match your case.

User job

How to use this calculator

Use Number Sequence Calculator when you need generated terms, then use target term and sum of generated terms to check the context for quick number work, classwork, spreadsheet checks, and explaining a calculation to someone else.

Best for

  • Checking the core numeric relationship
  • Comparing the main result with supporting outputs
  • Reviewing a default example before entering your own sequence type and first term.

Check before relying

  • Confirm sign, decimal, percent, and rounding assumptions before copying the number.
  • Indexing starts at n = 1.
  • The step value is a common difference in arithmetic mode and a common ratio in geometric mode.
  • Source context: OpenStax, Rice University, reviewed 2026-05-26.

Next useful step

  • Quadratic Formula CalculatorUse next when the number relation task needs first root real part instead of generated terms.
  • Common Factor CalculatorUse next when the number relation task needs common factors instead of generated terms.
  • Ratio CalculatorUse next when the number relation task needs matching second value instead of generated terms.

Formula

Arithmetic sequences use a_n = a_1 + d(n - 1); geometric sequences use a_n = a_1 r^(n - 1). Key assumptions: Indexing starts at n = 1. The step value is a common difference in arithmetic mode and a common ratio in geometric mode. The calculator generates terms from a known formula; it does not infer formulas from arbitrary lists.

  • Arithmetic sequences use a_n = a_1 + d(n - 1); geometric sequences use a_n = a_1 r^(n - 1).
  • Indexing starts at n = 1.
  • The step value is a common difference in arithmetic mode and a common ratio in geometric mode.
  • Primary source context: OpenStax, Rice University.

Inputs

Enter sequence type, first term, common difference or ratio, and terms to generate for number checks, homework, spreadsheet review, and quick comparisons. Before calculating, choose the mode or method first because it can change which formula is applied and stay within the documented minimum and maximum ranges. Sequence type: Choose arithmetic for a common difference or geometric for a common ratio. First term: The first term is a1. Common difference or ratio: In arithmetic mode this is d; in geometric mode this is r. Terms to generate: Generate between 1 and 100 terms.

Sequence typeChoose arithmetic for a common difference or geometric for a common ratio.
First termThe first term is a1.
Common difference or ratioIn arithmetic mode this is d; in geometric mode this is r.
Terms to generateGenerate between 1 and 100 terms.
Target term indexIndexing starts at n = 1.

Example

Using the default inputs, Number Sequence Calculator returns generated terms of 2, 5, 8, 11, 14. Adjust sequence type, first term, common difference or ratio, and terms to generate to match your own scenario.

FAQ

How is generated terms calculated here?

Arithmetic sequences use a_n = a_1 + d(n - 1); geometric sequences use a_n = a_1 r^(n - 1). The first assumption to check is: Indexing starts at n = 1.

What does Generated terms mean for number sequence?

Use the primary result for the number sequence task, then check the secondary outputs for context. Secondary values such as target term, sum of generated terms, and formula are there to explain the primary answer, not to replace it.

What should I enter for Sequence type?

Choose arithmetic for a common difference or geometric for a common ratio. Choose the mode or method first because it can change which formula is applied and stay within the documented minimum and maximum ranges.

How does First term change generated terms?

The first term is a1. Changing it can alter generated terms because the formula uses the submitted inputs together. Also compare unit handling, rounding, included inputs, excluded inputs, and source version.

Why does the number sequence example show 2, 5, 8, 11, 14 for generated terms?

The default inputs produce 2, 5, 8, 11, 14 for generated terms. Treat that as a format and scale check, then replace every default value with your own inputs.

Why does rounding matter for generated terms?

Rounding affects the displayed answer and can compound if you reuse the number. Keep more precision for intermediate work when the next step depends on it.

Sources

Last reviewed: 2026-05-26

  • Reviewed 2026-05-26
    College Algebra 2e, Section 9.2: Arithmetic SequencesOpenStax, Rice University. Common difference, recursive formula, and explicit formula a_n = a_1 + d(n - 1).
    Scope
    English-language algebra source for arithmetic sequence definitions and formulas.
    Supports
    Common difference, recursive formula, and explicit formula a_n = a_1 + d(n - 1).
    Limits
    This packet does not infer arbitrary patterns from pasted lists.
  • Reviewed 2026-05-26
    College Algebra 2e, Section 9.3: Geometric SequencesOpenStax, Rice University. Common ratio and explicit formula a_n = a_1 r^(n - 1).
    Scope
    English-language algebra source for geometric sequence definitions and formulas.
    Supports
    Common ratio and explicit formula a_n = a_1 r^(n - 1).
    Limits
    This packet handles finite displayed terms and does not address convergence or infinite series.