等差数列計算機

共有リンク

はじめに

Arithmetic Sequence Calculator — Compute the nth term and sum of an arithmetic sequence. Enter First term, Common difference, n to get an instant, accurate result.

計算式

nth term = a₁ + (n−1)d. Sum of first n terms = (n/2) × (2a₁ + (n−1)d), where a₁ is the first term and d is the common difference.

ステップごとの説明

Enter the First term.
Enter the Common difference.
Enter the n.
Click Calculate to see your result instantly.

実例

Example: With First term = 2, Common difference = 3, n = 10, the Arithmetic Sequence Calculator gives Nth Term: 29, Sum: 155.

よくある質問

What is the common difference?

The fixed amount added to each term to get the next one — it can be positive, negative, or a fraction.

How is the sum formula derived?

It's the average of the first and nth term, multiplied by the number of terms.

What inputs does the Arithmetic Sequence Calculator need?

You'll need to provide: First term, Common difference, n. All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.

How accurate is the Arithmetic Sequence Calculator?

The Arithmetic Sequence Calculator applies the formula exactly as calculated — nth term = a₁ + (n−1)d. Sum of first n terms = (n/2) × (2a₁ + (n−1)d), where a₁ is the first term and d is the common difference. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.

Is the Arithmetic Sequence Calculator free to use?

Yes, the Arithmetic Sequence Calculator is completely free, requires no signup, and runs instantly in your browser.