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Two numbers stacked in tall brackets with no dividing line.
Also known as: Quadratic residue symbol, Numbers stacked in brackets, Legendre quadratic symbol
The Legendre symbol looks exactly like a fraction and is not one: it takes the values 1, −1 or 0 according to whether the top number is a square modulo the bottom prime. The absent horizontal rule is the only visual difference from a binomial coefficient.
Denotes whether an integer is a quadratic residue modulo an odd prime: 1 if it is, −1 if not, 0 if the prime divides it.
Contexts: Mathematics
Is not a fraction despite its appearance, and is distinguished from the binomial coefficient only by context, both being stacked pairs without a rule.
Contexts: Mathematics
Underlies quadratic reciprocity, the theorem Gauss called the golden theorem and proved eight separate ways.
Contexts: Mathematics
Two numerals set one above the other inside a tall pair of curved brackets, with no horizontal rule between them.