Method
Arithmetic aₙ = a₁ + (n−1)d. Geometric aₙ = a₁r^(n−1). Closed-form sum formulas are used for the first n terms.
Math worksheet
Number Sequence Calculator
Generate arithmetic or geometric sequences, inspect the explicit n-th-term rule, partial sum and growth pattern.
The calculation runs locally. Exact-integer tools avoid floating point; decimal and transcendental tools report rounding limits.
Method and verification guide
How the Number Sequence Calculator works
Arithmetic aₙ = a₁ + (n−1)d. Geometric aₙ = a₁r^(n−1). Closed-form sum formulas are used for the first n terms. The calculator keeps the intermediate values visible so you can reproduce the answer independently.
Interpret the result
A constant difference indicates arithmetic change; a constant ratio indicates multiplicative change.
Check the assumptions
This generates an assumed sequence type; it does not infer a unique rule from arbitrary terms.
Local calculation
Everything runs in this browser. Inputs are not sent to an external calculator.
Rounding
Displayed values may be rounded for readability while calculations use full floating-point precision unless the tool explicitly uses exact integers.
Scope
This generates an assumed sequence type; it does not infer a unique rule from arbitrary terms.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.