%I A006052 M5482
%S A006052 1,0,1,880,275305224
%N A006052 Number of different magic squares of order n that can be formed from 
               the numbers 1, ..., n^2.
%C A006052 a(4) computed by Frenicle de Bessy in 1693.
%C A006052 a(5) computed by Richard Schroeppel in 1973.
%C A006052 According to Pinn and Wieczerkowski, a(6) = (0.17745 +- 0.00016) * 10^20. 
               - R. K. Guy, May 01, 2004.
%D A006052 E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Vol. II, pp. 
               778-783 gives the 880 4 X 4 squares.
%D A006052 M. Gardner, Mathematical Games, Sci. Amer. Vol. 249 (No. 1, 1976), p. 
               118.
%D A006052 M. Gardner, Time Travel and Other Mathematical Bewilderments. Freeman, 
               NY, 1988, p. 216.
%D A006052 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A006052 I. Peterson, <a href="http://www.maa.org/mathland/mathtrek_10_18_99.html">
               Magic Tesseracts</a>
%H A006052 K. Pinn and C. Wieczerkowski, <a href="http://www.arXiv.org/abs/cond-mat/
               9804109">Number of magic squares from parallel tempering Monte Carlo</
               a>, Internat. J. Modern Phys., 9 (4) (1998) 541-546.
%H A006052 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               MagicSquare.html">Link to a section of The World of Mathematics.</
               a>
%H A006052 <a href="Sindx_Mag.html#magic">Index entries for sequences related to 
               magic squares</a>
%e A006052 An illustration of the unique square of order 3:
%e A006052 |---+---+---|
%e A006052 | 2 | 7 | 6 |
%e A006052 |---+---+---|
%e A006052 | 9 | 5 | 1 |
%e A006052 |---+---+---|
%e A006052 | 4 | 3 | 8 |
%e A006052 |---+---+---|
%Y A006052 Sequence in context: A063051 A118799 A024393 this_sequence A105976 A137064 
               A092675
%Y A006052 Adjacent sequences: A006049 A006050 A006051 this_sequence A006053 A006054 
               A006055
%K A006052 nonn,hard,nice,more
%O A006052 1,4
%A A006052 N. J. A. Sloane (njas(AT)research.att.com).