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%I #14 Mar 04 2018 21:17:44
%S 1,1,1,5,7,42,22,429,715,4862,8398,58786,52003,742900,1337220,646323,
%T 17678835,129644790,79606450,1767263190,328206021,8155422340,
%U 45741281820,343059613650,107492012277,4861946401452,9183676536076
%N Second column and subdiagonal of number triangle A098509.
%F a(n) = denominator(n(n+1)/binomial(2n, n)).
%F a(n) = denominator(n/C(n)). - _Paul Barry_, Nov 17 2004
%F a(n) = C(n) / gcd(n, C(n)). - _Peter Luschny_, Oct 06 2011
%p C := n -> binomial(2*n,n)/(n+1):
%p A098512 := n -> C(n)/igcd(n,C(n)): # _Peter Luschny_, Oct 06 2011
%Y Cf. A093526, A093527, A000108.
%K easy,nonn
%O 0,4
%A _Paul Barry_, Sep 11 2004