%I A048872
%S A048872 1,2,4,17
%N A048872 Number of non-isomorphic arrangements of n lines in the real projective 
               plane such that the lines do not all pass through a common point.
%D A048872 J. E. Goodman and J. O'Rourke, editors, Handbook of Discrete and Computational 
               Geometry, CRC Press, 1997, p. 102.
%D A048872 B. Gr\"{u}nbaum, Arrangements and Spreads. American Mathematical Society, 
               Providence, RI, 1972, p. 4.
%H A048872 N. J. A. Sloane, <a href="a048872.pdf">Illustration of a(3) - a(6)</a> 
               [based on Fig. 2.1 of Gr\"{u}nbaum, 1972]
%Y A048872 See A132346 for the sequence when we include the arrangement where the 
               lines do pass through a common point, which is 1 greater than this.
%Y A048872 Cf. A003036, A048873, A132346.
%Y A048872 Sequence in context: A001128 A124436 A014221 this_sequence A105510 A155951 
               A118242
%Y A048872 Adjacent sequences: A048869 A048870 A048871 this_sequence A048873 A048874 
               A048875
%K A048872 nonn,bref,nice,more
%O A048872 3,2
%A A048872 N. J. A. Sloane (njas(AT)research.att.com).