Sequences Calculator

Explore arithmetic and geometric sequences — find the nth term and sum with a bar chart

a_n = 2 + (n−1)×3 | S_n = n/2 × (2×2 + (n−1)×3)

nth term

Sum of first n terms

100

First terms (8)

2, 5, 8, 11, 14, 17, 20, 23

About this calculator

The Sequences Calculator finds the nth term and sum of any arithmetic or geometric sequence and charts the first several terms as a bar graph. Enter the first term, common difference or ratio, and the position you want to reach. Useful for algebra, financial projections, and exploring patterns in mathematics.

Common examples

Arithmetic: a₁=2, d=3, n=10 → 10th term = 29, sum of 10 terms = 155
Geometric: a₁=3, r=2, n=5 → 5th term = 48, sum of 5 terms = 93
Arithmetic: a₁=10, d=−2, n=8 → 8th term = −4, sum of 8 terms = 24
Geometric: a₁=1, r=0.5, n=6 → 6th term ≈ 0.03125, sum of 6 terms ≈ 1.96875
Arithmetic: a₁=100, d=7, n=15 → 15th term = 198, sum of 15 terms = 2,235