Online Tool Store
Number Sequence Finder
Detect arithmetic, geometric, Fibonacci, square, cube, triangular, quadratic, or cubic patterns with a difference table and predict up to 10 next terms.
This works right here on your device — nothing gets sent out.
Enter at least 3 numbers to detect the pattern.
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Predicted next terms
How it works
- Enter at least 3 numbers in order.
- Choose how many next terms to predict — 3, 5, or 10.
- The tool checks common patterns and reports the first match, along with a difference table showing the math behind it.
- Copy the pattern name, rule, and predicted terms with one click.
The patterns checked
Arithmetic: aₙ₊₁ − aₙ = constant Geometric: aₙ₊₁ ÷ aₙ = constant Fibonacci-like: aₙ = aₙ₋₁ + aₙ₋₂ Squares: aₙ = n² Cubes: aₙ = n³ Triangular numbers: aₙ = n(n+1)/2 Quadratic: 2nd difference is constant Cubic: 3rd difference is constant
FAQ
What patterns can this detect?
Arithmetic (constant difference), geometric (constant ratio), Fibonacci-like (each term is the sum of the previous two), perfect squares, perfect cubes, triangular numbers, quadratic sequences (constant 2nd difference), and cubic sequences (constant 3rd difference) — the most common sequence types in math puzzles and coursework.
What if my sequence isn't recognized?
Some sequences follow patterns too complex or unusual for this detector (alternating rules, multi-step recurrences, etc.) — try entering more terms, or the pattern may need manual analysis.
How many numbers do I need to enter?
At least 3, though more terms give the detector more confidence — a 3-term arithmetic match could coincidentally also fit another pattern with a different next term. Cubic sequences need at least 4 terms since they're identified from a 3rd difference.
Can I see how the pattern was worked out?
Yes — once a pattern is found, a difference table shows the 1st, 2nd, and 3rd differences between your terms, so you can verify the match yourself instead of taking the result on faith.
How many next terms can I predict?
Choose 3, 5, or 10 upcoming terms from the dropdown above the input. Every predicted term is generated from the same detected rule, so accuracy doesn't drop off the further out you go.
Is my data uploaded anywhere?
No — pattern detection happens entirely in your browser. Nothing is sent to a server.
How we compare
| Feature | Online Tool Store | Manual pattern-spotting | Full CAS (computer algebra system) |
|---|---|---|---|
| Instant, no math background needed | ✓ | Requires spotting the pattern yourself | ✓ |
| No install | ✓ | ✓ | Requires dedicated software |
| Detects cubic and triangular-number sequences, not just the basics | ✓ | Requires knowing the formula to check | ✓ |
| Shows the difference table behind the answer | ✓ | You calculate it by hand | ✓ |
For a quick homework check or puzzle-solving aid, this beats opening a full computer algebra system for a simple sequence.