A173867 Largest prime < n-th Catalan number.

3, 13, 41, 131, 421, 1429, 4861, 16787, 58771, 208009, 742897, 2674429, 9694843, 35357657, 129644783, 477638699, 1767263171, 6564120403, 24466266973, 91482563633, 343059613639, 1289904147227, 4861946401451, 18367353072143

Offset: 3

Author

Vladimir Joseph Stephan Orlovsky, Feb 28 2010

Keywords

• nonn

Crossrefs

Cf. A000108.

Programs

Mathematica

PrimePrev[n_] := Module[{k=n-1}, While[ !PrimeQ[k], k--]; k]; f[n_] := (2n)!/n!/(n+1)!; Table[PrimePrev[f[n]], {n, 40}]
NextPrime[#,-1]&/@CatalanNumber[Range[3,30]] (* Harvey P. Dale, Sep 19 2012 *)