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 A125698 #5 Feb 16 2025 08:33:04 %S A125698 1,2,8,41,258,2407 %N A125698 Number of connected categories with n morphisms. %C A125698 Connected in the sense that if the morphism direction and composition is ignored, resulting in a multigraph, that multigraph is connected. %C A125698 Inverse Euler transform of A125696. %H A125698 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Category.html">Category</a> %e A125698 The 8 categories with 3 morphisms consist of 7 3-element monoids and one 2-object category with a single morphism between the objects. %Y A125698 Cf. A125696, A125699, A125700. %K A125698 hard,more,nonn %O A125698 1,2 %A A125698 _Franklin T. Adams-Watters_ and _Christian G. Bower_, Jan 05 2007