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Repeated terms of (2n)! (A010050).
1

%I #24 Sep 08 2022 08:46:10

%S 1,1,2,2,24,24,720,720,40320,40320,3628800,3628800,479001600,

%T 479001600,87178291200,87178291200,20922789888000,20922789888000,

%U 6402373705728000,6402373705728000,2432902008176640000,2432902008176640000,1124000727777607680000

%N Repeated terms of (2n)! (A010050).

%C For n>1, a(n) is the product of the smallest parts in the partitions of 4*floor(n/2) = A168273(n) into two parts.

%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>

%F a(n) = ( 2*floor(n/2) )! = A000142(A052928(n)).

%F a(2n) = a(2n+1) = A010050(n) = A211374(2n-1).

%F E.g.f.: log((1+x)/(1-x))/2+1/(1-x^2). - _Robert Israel_, Oct 19 2014

%p A248812:=n->(2*floor(n/2))!: seq(A248812(n), n=0..20);

%t Table[(2*Floor[n/2])!, {n, 0, 20}]

%o (Magma) [Factorial(2*Floor(n/2)) : n in [0..20]];

%Y Cf. A000142, A052928, A010050, A168273, A211374.

%K nonn,easy

%O 0,3

%A _Wesley Ivan Hurt_, Oct 16 2014