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 A264153 a(n) = ((2*n)!)^2 / 2^n. 0

%I

%S 1,2,144,64800,101606400,411505920000,3585039575040000,

%T 59375425441812480000,1710012252724199424000000,

%U 80059353648041568632832000000,5780285333388601255290470400000000,616883611349898303167109582028800000000,93983451956379706284115479041251737600000000

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

%F a(n) = A134372(n)/A000079(n).

%F a(n)*A264152(n) = A134372(n)*A006882(2*n-1)/A006882(n).

%F a(n)/A264152(n) is integer 1, 1, 24, 1620,....

%p a := n -> (2*n)!^2/2^n; seq(a(n), n=0..10);

%o (Sage)

%o a = lambda n: factorial(2*n)^2 >> n

%o [a(n) for n in range(11)]

%Y Cf. A000079, A000680, A134372, A264152.

%K nonn

%O 0,2

%A _Peter Luschny_, Nov 06 2015

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Last modified January 23 15:08 EST 2021. Contains 340385 sequences. (Running on oeis4.)