login
Numbers n such that n-th Catalan number is squarefree.
4

%I #12 Mar 25 2015 00:25:58

%S 1,2,3,4,5,7,8,9,11,17,19,31,35

%N Numbers n such that n-th Catalan number is squarefree.

%C No more terms < 10000. - _Robert G. Wilson v_, Aug 28 2004

%H C. Rivera, <a href="http://www.primepuzzles.net/problems/prob_043.htm">Problem 43. Catalan Numbers</a> in www.primepuzzles.net

%t Select[Range[500], SquareFreeQ[CatalanNumber[ # ]] &]

%Y Cf. A000108.

%K nonn

%O 1,2

%A _Joseph L. Pe_, Mar 01 2003

%E Mathematica updated by _Jean-François Alcover_, Jul 04 2013