%I A005650 M2704
%S A005650 1,1,3,7,47,207,2249,14501,216273,1830449,34662523,362983263,
%T A005650 8330310559,103938238111,2801976629841,40574514114061,1256354802202337,
%U A005650 20708839411614753,724160187180691379,13386284447024070647
%N A005650 Number of "magic squares" of order n (see comment line for exact definition).
%C A005650 This is the number of n X n square arrays with nonnegative integer entries 
               in which every row and column add to 2 (A000681) normalized by dividing 
               by n!/2^[n/2].
%D A005650 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005650 L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 125, #25, A_n.
%H A005650 <a href="Sindx_Mag.html#magic">Index entries for sequences related to 
               magic squares</a>
%F A005650 a(n) = A000681(n)*2^[n/2]/n!.
%Y A005650 Sequence in context: A007670 A074714 A064457 this_sequence A020754 A052381 
               A031440
%Y A005650 Adjacent sequences: A005647 A005648 A005649 this_sequence A005651 A005652 
               A005653
%K A005650 nonn,nice,easy
%O A005650 0,3
%A A005650 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com)
%E A005650 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 11 2001