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, 69533550915991, 263747951750333, 1002242216651359

Offset

3,1

Links

Amiram Eldar, Table of n, a(n) for n = 3..1000

Formula

From Amiram Eldar, Sep 24 2025: (Start)

a(n) = prime(A273974(n)) for n >= 4.

a(n) = A151799(A000108(n)).

a(n) = A151799(A173868(n)). (End)

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 *)

Crossrefs

Cf. A000108, A151799, A173868, A273974.

Sequence in context: A241527 A392083 A234387 * A121162 A146018 A145946

Adjacent sequences: A173864 A173865 A173866 * A173868 A173869 A173870

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Feb 28 2010

Extensions

More terms from Amiram Eldar, Sep 24 2025

Status

approved