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a(n)=(2n)!/n!-(2n)!/(n-1)!.
1

%I #9 Nov 21 2013 12:48:58

%S 1,0,-12,-240,-5040,-120960,-3326400,-103783680,-3632428800,

%T -141145804800,-6033983155200,-281585880576000,-14248245557145600,

%U -777177030389760000,-45464856277800960000,-2839804869044183040000,-188644180586506444800000

%N a(n)=(2n)!/n!-(2n)!/(n-1)!.

%C Row sums of number triangle A119836.

%F a(n)=A001813(n)-2*A001814(n).

%t f[n_]:=Module[{n2f=(2n)!},n2f/n!-n2f/(n-1)!]; f/@Range[0,20] (* _Harvey P. Dale_, Feb 13 2011 *)

%K easy,sign

%O 0,3

%A _Paul Barry_, May 25 2006