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

1,3

Comments

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

Links

Table of n, a(n) for n=1..13.

Eric Weisstein's World of Mathematics, Central Binomial Coefficient

Eric Weisstein's World of Mathematics, Squarefree

Mathematica

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

Prog

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

Crossrefs

Cf. A001405.

Cf. A056651 (cubefree central binomial coefficients).

Sequence in context: A293441 A306203 A111795 * A258085 A247350 A057484

Adjacent sequences: A046095 A046096 A046097 * A046099 A046100 A046101

Keyword

nonn,hard

Author

Eric W. Weisstein

Extensions

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

Status

approved