Algebra & Equations

Geometric Sequence Term

nth term of a geometric sequence.

Formula

Formula
an = a1 · rn−1

Variables

SymbolDefinitionType & rangeUnitsRole
a₁ first term computed result result
r common ratio real number (ℝ) input
n term index integer (ℤ) input

Try it yourself

Interactive calculator
Result

Worked examples

Example 1
Givenfirst term a₁ = 2, ratio r = 3, n = 6
Result486
Example 2
Givenfirst term a₁ = 1, ratio r = 0.5, n = 5
Result0.0625