115760628606domain: NAppears in sequencesa(n) = lcm(1, 2, ..., 2n) / lcm(1, 2, ..., n).at n=25A093880a(n) = lcm(1, 2, ..., 2n) / lcm(1, 2, ..., n).at n=26A093880The radical of the Catalan number which is the largest squarefree number dividing binomial(2*n,n)/(n+1).at n=25A281594