Everyday utility

Number Sequence Calculator

Calculate the nth term and sum of arithmetic (add constant) or geometric (multiply constant) sequences. Use this Data and utilities tool to enter your numbers, review the result, and understand the key assumptions before making the next decision.

What you get
A focused calculator, clear explanation, common questions, and useful next tools.
Quick intro
Calculator
Result
Explanation
Common questions
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How this calculator works
The result depends on the numbers you enter and the assumptions shown below.

Arithmetic sequence: aₙ = a₁ + (n−1)d; Sum = n(a₁+aₙ)/2. Geometric sequence: aₙ = a₁×rⁿ⁻¹; Sum = a₁(1−rⁿ)/(1−r). Used in finance (annuities), physics, and pattern recognition.

Review the inputs carefully and treat the output as an estimate. For decisions involving money, taxes, health, law, or security, compare the result with trusted professional guidance when needed.

Frequently asked questions

What is the difference between arithmetic and geometric sequences?

Arithmetic sequences add a constant (d) each step: 2, 5, 8, 11... Geometric sequences multiply by a constant (r) each step: 2, 6, 18, 54...