A046098 Numbers n such that central binomial coefficient C(n, floor(n/2)) is squarefree.

0, 1, 2, 3, 4, 5, 7, 8, 11, 17, 19, 23, 71

Offset: 1

Author

Eric W. Weisstein

Keywords

• nonn
• hard

Comments

No other n < 10^8. - T. D. Noe, Apr 06 2007

Links

• Eric Weisstein's World of Mathematics, Central Binomial Coefficient
• Eric Weisstein's World of Mathematics, Squarefree

Crossrefs

Cf. A001405.

Cf. A056651 (cubefree central binomial coefficients).

Programs

Mathematica

Select[Range[0, 100], SquareFreeQ[Binomial[#,Floor[#/2]]]&] (* Harvey P. Dale, Mar 11 2011 *)

PARI

is(n)=issquarefree(binomial(n,n\2)) \\ Charles R Greathouse IV, Jul 16 2011

Extensions

0 added by T. D. Noe, Mar 06 2014