A216629 - OEIS

%I #4 Sep 19 2012 02:23:02

%S 1,1,2,12,18,540,1200,168000,735000,463050000,4667544000,

%T 12938431968000,332086420512000,3989022083190144000,

%U 279394363051195392000,14383221809875538780160000,2892376010829659126572800000,632822947409421120302862912000000

%N  a(n) = A163085(n)/(floor(n/2)!)^2.

%o (Sage)

%o def A216629(n): return A163085(n)/factorial(n//2)^2

%o [A216629(n) for n in (0..17)]

%Y Cf. A069651.

%K nonn

%O 0,3

%A _Peter Luschny_, Sep 18 2012