9694843domain: NPropertiesPrimalityPrimeyesAppears in sequencesCatalan numbers minus 2.at n=15A120304Largest prime < n-th Catalan number.at n=12A173867Catalan numbers - 2 (A120304) with first three terms changed to 1,1,1.at n=15A289652Catalan numbers - 2 (A120304) with first four terms changed to 1,1,1,4.at n=15A289653Prime numbersat n=645742