%I A003213 M3987
%S A003213 1,5,37,782,44240
%N A003213 Number of ways to quarter a 2n X 2n chessboard.
%D A003213 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A003213 M. Gardner, The Unexpected Hanging and Other Mathematical Diversions. 
               Simon and Schuster, NY, 1969, p. 189.
%D A003213 T. R. Parkin, personal communication.
%D A003213 Popular Computing, Vol. 1 (No. 7, 1973), front cover and page 2.
%H A003213 <a href="a3213.jpg">Illustration showing that a(3) = 37.</a>
%Y A003213 Bisection of A006067. Cf. A064941.
%Y A003213 Sequence in context: A095957 A121834 A083846 this_sequence A166851 A090439 
               A089795
%Y A003213 Adjacent sequences: A003210 A003211 A003212 this_sequence A003214 A003215 
               A003216
%K A003213 nonn,nice
%O A003213 1,2
%A A003213 N. J. A. Sloane (njas(AT)research.att.com).