%I A001933 M0171 N0066
%S A001933 2,1,4,7,24,62,216,710,2570,9215,34146,126853,477182
%N A001933 Chessboard polyominoes with n squares.
%D A001933 W. F. Lunnon, personal communication.
%D A001933 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A001933 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%Y A001933 Sequence in context: A007839 A045625 A146004 this_sequence A038557 A011234 
               A128412
%Y A001933 Adjacent sequences: A001930 A001931 A001932 this_sequence A001934 A001935 
               A001936
%K A001933 hard,nonn
%O A001933 1,1
%A A001933 N. J. A. Sloane (njas(AT)research.att.com).