Special Number Generator
Generate square / cube / triangular / prime / Fibonacci / perfect numbers in one click. Every value uses big-integer maths, so long results stay exact.
Type:   Start Index:   How Many:
Sort by:   Separator:
Output Result
Generated Number Download CSV
No. Result Expression

Introduction to the tool and how to use it

Special Number Generator lists the classic families of patterned numbers in one go — handy for maths practice, worksheets, checking a sequence, or just seeing what a huge number looks like. Supported types:
1. Square numbers: n × n → 1, 4, 9, 16 …;
2. Cube numbers: n × n × n → 1, 8, 27, 64 …;
3. Triangular numbers: n × (n+1) ÷ 2 → 1, 3, 6, 10 …;
4. Primes: the n-th prime in order → 2, 3, 5, 7, 11 …;
5. Fibonacci numbers: F(1)=1, F(2)=1, each later term is the sum of the previous two → 1, 1, 2, 3, 5, 8 …;
6. Perfect numbers: equal to the sum of their proper divisors → 6, 28, 496, 8128 … computed instantly with the Euclid formula 2^(p-1) × (2^p - 1).

Steps:
1. Pick a Type;
2. Set Start Index — which term to begin at, e.g. 5 for triangular numbers starts at T(5)=15;
3. Set Generate Count;
4. Optionally choose a Sort By: keep original order (by index), ascending or descending;
5. Set the separator — the default \n puts one number per line, a comma joins them on one line;
6. Click Run. Results appear in the text box and in the table below (index / value / formula), with CSV export.
Note: every value is computed with big integers, so long terms never suffer floating-point error or scientific notation. Primes go up to the 100000th, Fibonacci up to term 5000, and perfect numbers are limited to the 12 known Mersenne exponents; a start index beyond the range restarts from the beginning and shows a hint.

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