ToolsDoc

Number Sequence Calculator

Nth term and sum of an arithmetic sequence.

Worth Knowing

This handles arithmetic sequences, where each term increases by a fixed common difference. Its neat result is the sum formula — average the first and last terms and multiply by how many there are — the shortcut a young Gauss reputedly used to add 1 through 100 in seconds. Arithmetic sequences model anything that grows by equal steps, from stacked seating rows to simple-interest balances, in contrast to geometric sequences that grow by a fixed ratio.

How to Use

  1. Enter First term into the first field of the Number Sequence Calculator.
  2. Fill in the rest: Common difference, Number of terms (n).
  3. Your result appears instantly as you type — there's no submit button or page reload.

Frequently Asked Questions