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 A288563 #12 Jul 09 2025 04:44:27 %S A288563 1,1,3,14,200,30630 %N A288563 Number of one-sided arrangements of n pseudo-circles in the affine plane. %C A288563 These counts have not been reduced for mirror symmetry. %C A288563 See A250001, the main entry for this problem, for further information. %Y A288563 Cf. A250001, A275923, A275924, A288554-A288568. %K A288563 nonn,more %O A288563 0,3 %A A288563 _N. J. A. Sloane_, Jun 13 2017, based on information supplied by _Jon Wild_ on Aug 31 2016