OFFSET
0,4
FORMULA
a(n) = denominator(n(n+1)/binomial(2n, n)).
a(n) = denominator(n/C(n)). - Paul Barry, Nov 17 2004
a(n) = C(n) / gcd(n, C(n)). - Peter Luschny, Oct 06 2011
MAPLE
C := n -> binomial(2*n, n)/(n+1):
A098512 := n -> C(n)/igcd(n, C(n)): # Peter Luschny, Oct 06 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Sep 11 2004
STATUS
approved