A072118 - OEIS

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A072118

a(n) = (2*n)!/core(n!)^2/(n+1) where core(x) is the squarefree part of x.

%I #6 Mar 30 2012 18:39:03

%S 1,2,5,224,672,2737152,8895744,474439680,130660687872,

%T 4513732853760000,15798064988160000,894413525483520000,

%U 3194334019584000000,27610545531676262400000,8107146431738442547200000

%N a(n) = (2*n)!/core(n!)^2/(n+1) where core(x) is the squarefree part of x.

%o (PARI) for(n=1,50,print1((2*n)!/core(n!)^2/(n+1),","))

%K easy,nonn

%O 1,2

%A _Benoit Cloitre_, Jun 19 2002