Number Sequence Calculator

Arithmetic or geometric sequence term and sum.

Number Sequence Calculator helps you arithmetic or geometric sequence term and sum. Enter first term (a₁), common difference / ratio, and term number n, review the breakdown, and use the guidance below to understand what the number means — and what it does not. What the Number Sequence calculator does Number Sequence Calculator is built for arithmetic, algebra, geometry, and number tools. Arithmetic or geometric sequence term and sum. You enter first term (a₁), common difference / ratio, and term number n, then Simple Calculators computes the result instantly. Results use standard school and engineering formulas that run privately in your browser. How the math works Choose the Type, then enter the First term (a₁), the Common difference (d) or Common ratio (r), and the Term number n. For an arithmetic sequence the calculator adds d each step: term n = a₁ + (n − 1) × d, and the sum = n ÷ 2 × (first term + term n). For a geometric sequence it multiplies by r each step: term n = a₁ × r^(n − 1), and the sum = a₁ × (rⁿ − 1) ÷ (r − 1). The term number is rounded to a whole number, and a table lists up to the first 20 terms with a running total. The formula: Arithmetic: aₙ = a₁ + (n − 1) ×…