A080397 Largest squarefree number dividing central binomial coefficient A000984(n).

1, 2, 6, 10, 70, 42, 462, 858, 4290, 24310, 92378, 176358, 1352078, 520030, 222870, 6463230, 200360130, 129644790, 907513530, 1767263190, 22974421470, 134564468610, 526024740930, 22870640910, 1074920122770, 1504888171878, 1967930686302, 34766775458002, 1912172650190110

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..1000

Formula

a(n) = A007947(A000984(n)).

Maple

a := n -> convert(numtheory:-factorset(binomial(2*n, n)), `*`):
seq(a(n), n=0..25); # Peter Luschny, Oct 31 2015

Mathematica

a[n_] := Times @@ FactorInteger[Binomial[2n, n]][[All, 1]]; Array[a, 26, 0] (* Jean-François Alcover, Jun 04 2019 *)

Prog

(PARI) a(n) = vecprod(factor(binomial(2*n, n))[, 1]); \\ Amiram Eldar, Jun 21 2024

Crossrefs

Cf. A007947, A000984, A001405, A048633.

Sequence in context: A361792 A324547 A093880 * A322756 A048782 A358739

Adjacent sequences: A080394 A080395 A080396 * A080398 A080399 A080400

Keyword

nonn

Author

Labos Elemer, Mar 19 2003

Extensions

More terms from Amiram Eldar, Jun 21 2024

Status

approved