Formula and calculation method
Arithmetic: aₙ = a₁ + (n−1)d. Geometric: aₙ = a₁r^(n−1).
Use consistent units for all comparable inputs. The displayed result is rounded; arithmetic is performed with the full available numeric precision. Check your source measurements before relying on the result.
How to use number sequence calculator
- Set First term. The example below uses 2.
- Set Common difference or ratio. The example below uses 3.
- Set Number of terms. The example below uses 10.
- Set Sequence type by choosing the option that matches your calculation.
- Select Calculate to update the result. Reset restores the illustrated inputs. Copy, print or download your own result if you need a record.
Worked example
Example inputs
- First term
- 2
- Common difference or ratio
- 3
- Number of terms
- 10
- Sequence type
- Arithmetic
- Sequence
- 2, 5, 8, 11, 14, 17, 20, 23, 26, 29
- Sum
- 155
Factors affecting your result
Use consistent units for all comparable inputs. The displayed result is rounded; arithmetic is performed with the full available numeric precision. Check your source measurements before relying on the result.
Changing first term changes the scenario being evaluated. Adjust one input at a time when comparing results, keep a copy of the assumptions, and compare values using the same unit and period. A precise arithmetic result does not make an uncertain assumption precise.
Frequently asked questions
How does the number sequence calculator work?
Arithmetic: aₙ = a₁ + (n−1)d. Geometric: aₙ = a₁r^(n−1).
What inputs does Number Sequence Calculator need?
Enter first term, common difference or ratio, number of terms, sequence type. Choose values that correspond to the same situation and measurement convention.
How should I interpret the number sequence calculator result?
Use consistent units for all comparable inputs. The displayed result is rounded; arithmetic is performed with the full available numeric precision. Check your source measurements before relying on the result.
Are my number sequence calculator inputs uploaded?
No. The calculation runs in this browser. Favorites, recent tool names, theme and formatting preferences may be saved locally, but calculation inputs are not sent to a calculation server or stored by this website. Shared links do not include entered values.
Maintained by Calculators.buzz Editorial Team. Implementation date: . No professional credentials or clinical review are claimed. Read our methodology policy.