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 A196814 #8 Jul 22 2025 12:51:51 %S A196814 1,4,6,84,120,784,280,40816,13806,1361706,110990,142633176,4263454, %T A196814 197730660,9246172320 %N A196814 Number of ways to place n nonattacking nightriders on an n X n cylindrical board. %H A196814 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a> %Y A196814 Cf. A190393, A196810, A196811, A172141, A173429 %K A196814 nonn,hard %O A196814 1,2 %A A196814 _Vaclav Kotesovec_, Oct 06 2011