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Pronic number - mklabgr - 07-04-2026
Pronic number
Summary
A pronic number (also called an oblong or rectangular number) is any number that can be written as the product of two consecutive integers, in the form ($n(n+1)$). The sequence begins with $0, 2, 6, 12, 20, 30,$ and $42$, and these numbers can be visualized as perfect rectangles with sides of consecutive lengths, such as $(3 \times 4 = 12)$. Pronic numbers have fascinated mathematicians since ancient Greece and are closely connected to triangular numbers, with each pronic number being exactly twice a triangular number.
They also have several elegant properties—for example, every pronic number is even, 2 is the only one that is prime, and there is always a perfect square between any two consecutive pronic numbers—making them a beautiful example of the hidden patterns that appear throughout number theory.
ARTICLE