A080664 Numbers n such that n-th Catalan number is squarefree.

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

Offset: 1

Author

Joseph L. Pe, Mar 01 2003

Keywords

• nonn

Comments

No more terms < 10000. - Robert G. Wilson v, Aug 28 2004

Links

• C. Rivera, Problem 43. Catalan Numbers in www.primepuzzles.net

Crossrefs

Cf. A000108.

Programs

Mathematica

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

Extensions

Mathematica updated by Jean-François Alcover, Jul 04 2013