%I A034000
%S A034000 1,5,40,440,6160,104720,2094400,48171200,1252451200,36321084800,
%T A034000 1162274713600,40679614976000,1545825369088000,63378840132608000,
%U A034000 2788668965834752000,131067441394233344000,6553372069711667200000
%N A034000 One half of triple factorial numbers.
%F A034000 2*a(n+1) = (3*n+2)!!! := product(3*j+2, j=0..n), n >= 0; E.g.f. (-1+(1-3*x)^(-2/
               3))/2; a(n) = (3*n-1)!/(2*3^(n-1)*(n-1)!*A007559(n)).
%F A034000 a(n) ~ 3/2*2^(1/2)*pi^(1/2)*Gamma(2/3)^-1*n^(7/6)*3^n*e^-n*n^n*{1 + 23/
               36*n^-1 + ...}. - Joe Keane (jgk(AT)jgk.org), Nov 23 2001
%F A034000 a(n)=3^(n)*(n+2/3)!/(2/3)! - Paul Barry (pbarry(AT)wit.ie), Sep 04 2005
%Y A034000 Cf. A007559, A034001, A025748, A034724.
%Y A034000 Sequence in context: A061633 A143437 A083304 this_sequence A000359 A121886 
               A052868
%Y A034000 Adjacent sequences: A033997 A033998 A033999 this_sequence A034001 A034002 
               A034003
%K A034000 easy,nonn
%O A034000 1,2
%A A034000 Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)