OFFSET
1,2
COMMENTS
a(2k+1)=a(2k+2) unless 2k+1 is in A000225, in which case a(2k+2)=2*a(2k+1). - Robert Israel, Jan 21 2020
LINKS
Robert Israel, Table of n, a(n) for n = 1..3364
EXAMPLE
n=10: C(10,5)=252=2*2*3*3*7. The largest squarefree number dividing the 10th central binomial coefficient is 2*3*7=42. Thus a(10)=42
MAPLE
f:= n -> convert(numtheory:-factorset(binomial(n, floor(n/2))), `*`):
map(f, [$1..50]); # Robert Israel, Jan 21 2020
MATHEMATICA
Table[Last@ Select[Divisors@ Binomial[n, Floor[n/2]], SquareFreeQ], {n, 35}] (* Michael De Vlieger, Feb 05 2017 *)
PROG
(PARI) a(n)=factorback(factor(binomial(n, n\2))[, 1]) \\ Charles R Greathouse IV, Nov 05 2017
(Magma) [&*PrimeDivisors(Binomial(n, Floor(n/2))): n in [1..35]]; // Marius A. Burtea, Jan 21 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved