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%I #20 Apr 10 2018 23:53:18
%S 0,1,0,2,4,36,144,1440,8640,100800,806400,10886400,108864000,
%T 1676505600,20118067200,348713164800,4881984307200,94152554496000,
%U 1506440871936000,32011868528640000,576213633515520000,13380961044971520000,267619220899430400000
%N Number of permutations of [n] starting and ending with an odd number.
%H Alois P. Heinz, <a href="/A199495/b199495.txt">Table of n, a(n) for n = 0..175</a>
%F From _Alois P. Heinz_, Nov 07 2011: (Start)
%F a(n) = 2*(n-2)! * [x^(n-2)] x/((1+x)^2*(1-x)^3) for n>=2, else a(n) = n.
%F a(n) = 2*A152887(n-2) for n>=2, else a(n) = n. (End)
%p a:= n-> `if`(n<2, n, ceil(n/2)*(ceil(n/2)-1)*(n-2)!):
%p seq(a(n), n=0..30); # _Alois P. Heinz_, Nov 07 2011
%Y Cf. A052618, A077611, A152887.
%K nonn
%O 0,4
%A _Olivier Gérard_, Nov 07 2011
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