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 A006391 M1464 #19 Jan 16 2025 11:30:40 %S A006391 1,1,2,5,14,45,191,871,4682,27336,172706,1150322,7989004 %N A006391 Number of unsensed loopless planar maps with n edges. %D A006391 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006391 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 A006391 Cf. A006385, A000260 (rooted), A006390 (sensed). %K A006391 nonn %O A006391 0,3 %A A006391 _N. J. A. Sloane_ %E A006391 a(8)-a(12) from _Sean A. Irvine_, Mar 29 2017 %E A006391 a(0)=1 prepended by _Andrew Howroyd_, Jan 14 2025