Number Sequence Calculator
Identify and generate arithmetic, geometric, and other number sequences.
A number sequence calculator identifies the pattern in a series of numbers and predicts the next terms in the sequence.
Examples
Arithmetic
Geometric
Quadratic
Frequently Asked Questions
How are arithmetic sequences identified?
How are geometric sequences identified?
What if the pattern is not obvious?
Quick Tips
- •Double-check your inputs — small errors lead to incorrect results.
- •Enter at least 3 terms for more reliable pattern detection.
- •Use commas to separate values and avoid extra spaces or non-numeric characters.
A number sequence calculator identifies the pattern in a series of numbers and predicts the next terms in the sequence.
How to Use This Calculator
Enter a comma-separated sequence of numbers and how many next terms to predict. The calculator identifies whether the sequence is arithmetic, geometric, or quadratic, and predicts the next terms.
Understanding the Formula
Arithmetic: aₙ = a₁ + (n-1)d; Geometric: aₙ = a₁ × r^(n-1); where d = common difference, r = common ratio.
Examples
Arithmetic
2, 5, 8, 11: d = 3, next terms: 14, 17, 20, 23, 26
Geometric
3, 9, 27, 81: r = 3, next terms: 243, 729, 2187
Quadratic
1, 4, 9, 16: (perfect squares), next: 25, 36, 49
Frequently Asked Questions
How are arithmetic sequences identified?
A sequence is arithmetic if the difference between consecutive terms is constant. For example, 5, 10, 15, 20 has a constant difference of 5.
How are geometric sequences identified?
A sequence is geometric if the ratio between consecutive terms is constant. For example, 2, 6, 18, 54 has a constant ratio of 3.
What if the pattern is not obvious?
The calculator checks for constant first differences (arithmetic), constant ratios (geometric), and constant second differences (quadratic). If none match, it uses the last difference as an estimate.
Assumptions & Limitations
- Assumes the sequence follows an arithmetic, geometric, or quadratic pattern.
- Assumes exact input values; rounding in inputs propagates to results.
- Results may show floating-point approximations for irrational numbers.