%I A001508 M4918 N2111
%S A001508 0,0,0,0,13,252,3740,51300,685419,9095856,120872850,1614234960,21697730849
%N A001508 Number of simple quadrangulations.
%D A001508 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A001508 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A001508 R. C. Mullin and P. J. Schellenberg, The enumeration of c-nets via triangulations, 
               J. Combin. Theory, 4 (1968), 259-276.
%Y A001508 Sequence in context: A053100 A126422 A106738 this_sequence A157946 A034242 
               A142811
%Y A001508 Adjacent sequences: A001505 A001506 A001507 this_sequence A001509 A001510 
               A001511
%K A001508 nonn
%O A001508 1,5
%A A001508 N. J. A. Sloane (njas(AT)research.att.com).