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.

A384639 Number of equivalence classes (up to graph homeomorphism) of finite graphs that have an embedding in an orientable surface of genus n which minimally separates the surface (that is, no proper subset of the embedding separates the genus n surface).

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%I A384639 #59 Aug 19 2025 16:36:05
%S A384639 1,5,26,217,3555,118993
%N A384639 Number of equivalence classes (up to graph homeomorphism) of finite graphs that have an embedding in an orientable surface of genus n which minimally separates the surface (that is, no proper subset of the embedding separates the genus n surface).
%D A384639 C. N. Aagaard and J. J. P. Veerman, Classification of Minimal Separating Sets of Low Genus Surfaces, Topology and its Applications, Accepted, 2025.
%D A384639 J. Bernhard and J. J. P. Veerman, The Topology of Surface Mediatrices, Topology and its Applications, 154, 54-68, 2007.
%e A384639 For genus 0: only the circle.
%e A384639 For genus 1: 1 circle, 2 circles, bouquet of 2 circles, bouquet of 3 circles, 4-fold multi-edge.
%Y A384639 Cf. A387066, A387067, A387068.
%K A384639 more,nonn
%O A384639 0,2
%A A384639 _J. J. P. Veerman_, Aug 13 2025