A056058 Squarefree part of the n-th central binomial coefficient.

1, 2, 3, 6, 10, 5, 35, 70, 14, 7, 462, 231, 429, 858, 715, 1430, 24310, 12155, 92378, 46189, 88179, 176358, 1352078, 676039, 52003, 104006, 22287, 44574, 2154410, 1077205, 33393355, 66786710, 129644790, 64822395, 181502706, 90751353

Offset

1,2

Comments

a(3387) has 1001 decimal digits. - Michael De Vlieger, Jul 14 2017

Links

Michael De Vlieger, Table of n, a(n) for n = 1..3386

Formula

a(n) = A007913(A001405(n)).

For squarefree central binomial coefficients (A046098), a(n)=A001405(n).

Mathematica

Table[Sqrt[Binomial[n, Floor[n/2]]] /. (c_: 1) a_^(b_: 0) :> (c a^b)^2, {n, 36}] (* Michael De Vlieger, Jul 14 2017, after Bill Gosper at A007913 *)

Crossrefs

Cf. A048633 for another version.

Sequence in context: A191542 A191668 A056060 * A352722 A028255 A342766

Adjacent sequences: A056055 A056056 A056057 * A056059 A056060 A056061

Keyword

nonn

Author

Labos Elemer, Jul 26 2000

Status

approved