OFFSET
1,2
EXAMPLE
For n=10, the squarefree kernels of binomial(n,k) are {1, 10, 15, 30, 210, 42, 210, 30, 15, 10, 1}, so the maximal largest squarefree divisor is that of binomial(10,4)=210: it is 210, so a(10)=210. (It is not equal to the largest squarefree number dividing binomial(10,5)=252, which is A048633(10)=42.) [edited by Jon E. Schoenfield, May 19 2018]
PROG
(PARI) a(n) = vecmax(vector(ceil(n\2)+1, k, factorback(factorint(binomial(n, k-1))[, 1]))); \\ Michel Marcus, May 20 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved