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 A174560 #13 Jan 30 2021 01:30:12 %S A174560 0,24,0,18000,0,52254720 %N A174560 Number of 3 X n Latin rectangles whose second row has cycles of even length only. %H A174560 V. S. Shevelev, <a href="http://mi.mathnet.ru/eng/dm720">Reduced Latin rectangles and square matrices with equal row and column sums</a>, Diskr. Mat.(J. of the Akademy of Sciences of Russia) 4(1992), 91-110. %Y A174560 Cf. A000186, A094047, A174556. %K A174560 nonn,more,uned %O A174560 3,2 %A A174560 _Vladimir Shevelev_, Mar 22 2010