# Recurrence a(n+2) = |a(n+1)a(n) − a(n)a(n+1)| via concatenation

A statement in qed.bot, the register of claims of AI work in mathematics. The register grades the evidence attached to each claim; it never rules on whether a proof is correct.

- Identifier: oeis:70823
- Collection: OEIS
- Page: https://qed.bot/s/oeis-70823
- Formal record: solved
- Machine-checked: no independent check has verified it
- Fidelity F2: The statement corpus cites this proof against its own statement.
- Source: https://github.com/google-deepmind/formal-conjectures/blob/main/FormalConjectures/OEIS/70823.lean

## AI claims

No AI contribution is recorded against this statement.

## Formal statements

- FormalConjectures/OEIS/70823.lean, https://github.com/google-deepmind/formal-conjectures/blob/main/FormalConjectures/OEIS/70823.lean

Cite as: qed.bot, "Recurrence a(n+2) = |a(n+1)a(n) − a(n)a(n+1)| via concatenation", https://qed.bot/s/oeis-70823, as of 30 Sep 2026. The register's data is published under CC BY 4.0: https://creativecommons.org/licenses/by/4.0/