Calculate a sequence term and sum
An arithmetic progression adds the same common difference at every step. Enter an integer first term, an integer difference, and a positive term count. The calculator gives the last term, total sum, and a preview of the first 20 terms.
Formulas
For first term a, common difference d, and count n, the nth term is a + (n − 1)d. The sum is n(a + last term) / 2. For example, 3, 7, 11, … has a tenth term of 39 and a sum of 210.
Exact integers, including descending sequences
Use a negative difference for descending values or zero for a constant sequence. BigInt arithmetic keeps results exact. First term and difference accept up to 100 digits each; the term count is limited to 1,000,000,000. Decimal inputs are rejected. Only a short preview is generated, even for large counts. All calculations happen locally.