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%I #4 Apr 10 2017 12:38:13
%S 2,1,1,2,3,6,15,41,120,390,1356,5040,19885,82835,362880,1665838,
%T 7988888,39916800,207304279,1116669004,6227020800,35886673907,
%U 213407853923,1307674368000,8245960182039,53446811415730,355687428096000,2427977164711193,16984208960998390
%N Ceiling(Gamma(2n/3)).
%C There are two integer-valued interpolations between successive factorials.
%H Clark Kimberling, <a href="/A284999/b284999.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = ceiling(Gamma(2n/3)).
%t Table[Ceiling[Gamma[2n/3]], {n, 1, 35}]
%Y Cf. A000142, A284998.
%K nonn,easy
%O 1,1
%A _Clark Kimberling_, Apr 08 2017