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 A006389 M1632 #19 Jan 16 2025 14:17:24 %S A006389 1,1,2,6,18,68,313,1592,9187,57451,384450,2703970,19769311 %N A006389 Number of unsensed planar maps with n edges and without faces of degree 1. %D A006389 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006389 Timothy R. Walsh, <a href="http://dx.doi.org/10.1137/0604018">Generating nonisomorphic maps without storing them</a>, SIAM J. Algebraic Discrete Methods 4 (1983), no. 2, 161-178. %Y A006389 Cf. A006385, A006388 (sensed), A379433 (rooted). %K A006389 nonn,more %O A006389 0,3 %A A006389 _N. J. A. Sloane_ %E A006389 a(8)-a(12) from _Sean A. Irvine_, Mar 28 2017 %E A006389 a(0)=1 prepended by _Andrew Howroyd_, Jan 16 2025