# Number Sequence Calculator

> Find terms, partial sums, and a preview for arithmetic, geometric, or Fibonacci sequences.

Page: https://askcalculators.com/calculator/number-sequence-calculator/
Definition: https://askcalculators.com/calculator/number-sequence-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/number-sequence-calculator/schema.json
Version: 2.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/number-sequence-calculator/?sequenceType=arithmetic&firstTerm=1&commonValue=2&termNumber=10

## Inputs
- sequenceType: Sequence type; type=select; required; default=arithmetic; values=arithmetic|geometric|fibonacci
- firstTerm: First term; type=number; required; default=1
- commonValue: Common difference or ratio; type=number; required; default=2
- termNumber: Term number (n); type=number; required; default=10; min=1; max=1000

## Outputs
- nthTerm: n-th term; format=text; primary
- sum: Sum through n; format=text
- sequencePreview: First terms; format=text
- sequenceTypeLabel: Sequence type; format=text

## Formula
Arithmetic: aₙ=a₁+(n−1)d; geometric: aₙ=a₁rⁿ⁻¹; Fibonacci: Fₙ=Fₙ₋₁+Fₙ₋₂.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.