This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A132346 #7 Dec 12 2014 11:30:05 %S A132346 1,1,1,2,3,5,18 %N A132346 Number of nonisomorphic arrangements of n lines in the real projective plane, including the arrangement where all the lines pass through a common point. %C A132346 See the illustration of initial terms in A048872. %D A132346 J. E. Goodman and J. O'Rourke, editors, Handbook of Discrete and Computational Geometry, CRC Press, 1997, p. 102. %D A132346 B. Grünbaum, Arrangements and Spreads. American Mathematical Society, Providence, RI, 1972, p. 4. %Y A132346 Equals A048872 + 1. Cf. A003036, A048873. Different from A121510. %K A132346 nonn,nice,more %O A132346 0,4 %A A132346 _N. J. A. Sloane_, Nov 09 2007