The story
Named after German mathematician Carl Gustav Jakob Jacobi, who introduced the notation in 1837.
Etymology from Wiktionary, CC BY-SA 4.0.
Jacobi symbol
Today it means: A mathematical function of integer a and odd positive integer b, generally written (a/b), based on, for each of the prime factors pᵢ of b, whether a is a quadratic residue or nonresidue modulo pᵢ. Full definition →