cp's OEIS Frontend

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.

A275923 Number of connected arrangements of n circles in the affine plane, in the sense that the union of the solid circles is a connected set.

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%I A275923 #23 Jul 09 2025 04:41:47
%S A275923 1,1,2,11,156,16756
%N A275923 Number of connected arrangements of n circles in the affine plane, in the sense that the union of the solid circles is a connected set.
%C A275923 Arrangements in A250001 that are connected (in the sense that the union of the solid circles is a connected set). See A250001, the main entry for this problem, for further information.
%C A275923 Is this also 1 together with column 1 of A285996? - _Omar E. Pol_, May 28 2017
%H A275923 Jon Wild, <a href="/A275923/a275923.png">Figure showing relationship between A250001, A275923, A275924, and A288554 for n=3 circles</a>
%Y A275923 Cf. A250001, A275924, A288554-A288568.
%K A275923 nonn,more
%O A275923 0,3
%A A275923 _N. J. A. Sloane_, Aug 29 2016, based on information supplied by _Jon Wild_
%E A275923 a(5) from _Jon Wild_, Aug 31 2016