Mathematics Atlas

How Proof Is Made
Sign In
Text size
100%
Theme
Theorem

Cassini and Catalan Identities

Number Theory

Cassini's identity and Catalan's identity are related mathematical identities concerning the Fibonacci numbers, alongside a further generalization known as Vajda's identity. Cassini's identity, which is a special case of the other two, gives a formula relating the nth Fibonacci number to its neighbors in the sequence. Cassini's identity is named for the astronomer Giovanni Domenico Cassini, and Catalan's identity for the mathematician Eugene Catalan.

Facts
Statement
Cassini's identity, a special case of the other two, states that for the nth Fibonacci number, F(n-1) F(n+1) - F(n)^2 = (-1)^n. 1
Proof Year
1680 1
Classification
Statement Form
Identity or Equation 1
Connections

Has Statement Form

Equation, Concepts

Entity-backed identity for the statement-form enum value this theorem already carries, resolved to a mathematics concept by an explicit value-to-entity map (phase 3 bucket conversion, docs\design_entity_backed_browse_buckets_20260928.md). The statement-form fact itself stays on the theorem unchanged.

Identity, Concepts

Entity-backed identity for the statement-form enum value this theorem already carries, resolved to a mathematics concept by an explicit value-to-entity map (phase 3 bucket conversion, docs\design_entity_backed_browse_buckets_20260928.md). The statement-form fact itself stays on the theorem unchanged.

Sources
1. Cassini and Catalan identities - Wikipedia
  • Lead section
    Cassini's identity, a special case of the other two, states that for the nth Fibonacci number,
  • History section
    Cassini's formula was discovered in 1680 by Giovanni Domenico Cassini, then director of the Paris Observatory, and independently proven by Robert Simson (1753).
View the Source
Comments (0)
No comments yet. Be the first to share a thought.
Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.