%I A055209
%S A055209 1,1,4,144,82944,1194393600,619173642240000,15728001190723584000000,
%T A055209 25569049282962188245401600000000,3366980847587422591723894776791040000000000,
%U A055209 44337041641882947649156022595410930014617600000000000000
%N A055209 Product_{i=0..n} i!^2.
%C A055209 a(n) is the discriminant of the polynomial x(x+1)(x+2)...(x+n). - Yuval 
               Dekel (dekelyuval(AT)hotmail.com), Nov 13 2003
%C A055209 This is the Hankel transform (see A001906 for definition) of the sequence 
               : 1, 0, 1, 0, 5, 0, 61, 0, 1385, 0, 50521, ... (see A000364: Euler 
               numbers). Philippe DELEHAM, Apr 06 2005
%D A055209 R. Ehrenborg, The Hankel determinant of exponential polynomials, Amer. 
               Math. Monthly, 107 (2000), 557-560.
%D A055209 Michael Z. Spivey and Laura L. Steil, The k-Binomial Transforms and the 
               Hankel Transform, Journal of Integer Sequences, Vol. 9 (2006), Article 
               06.1.1.
%H A055209 J. W. Layman, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">
               The Hankel Transform and Some of its Properties</a>, J. Integer Sequences, 
               4 (2001), #01.1.5.
%H A055209 <a href="Sindx_Fa.html#factorial">Index entries for sequences related 
               to factorial numbers</a>
%H A055209 C. Radoux, <a href="http://www.mat.univie.ac.at/~slc/opapers/s28radoux.html">
               Determinants de Hankel et theoreme de Sylvester</a>
%F A055209 a(n) = A000178(n)^2. - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Mar 
               06 2004
%p A055209 seq(mul(mul(j^2,j=1..k), k=0..n), n=0..10); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Sep 21 2007
%Y A055209 A055209 is the Hankel transform (see A001906 for definition) of A000023, 
               A000142, A000166, A000522, A003701, A010842, A010843, A051295, A052186, 
               A053486, A053487 - John W. Layman (layman(AT)math.vt.edu) and Michael 
               Somos, Jul 27 2000
%Y A055209 Sequence in context: A122747 A069135 A138176 this_sequence A030450 A041629 
               A159197
%Y A055209 Adjacent sequences: A055206 A055207 A055208 this_sequence A055210 A055211 
               A055212
%K A055209 nonn,easy
%O A055209 0,3
%A A055209 N. J. A. Sloane (njas(AT)research.att.com), Jul 18 2000