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 A185056 #9 Sep 12 2015 11:00:24 %S A185056 1,2,5,24,125,796,5635,48042,453947,4834872,56433455,727449366, %T A185056 10099103269,152097526360,2449915208271,42295879864692 %N A185056 Number of ways to place n nonattacking composite pieces bishop + semi-rook on an n X n board. %C A185056 Two semi-rooks do not attack each other if they are in the same column. %H A185056 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a> %Y A185056 Cf. A088789, A187235, A002465, A099152, A000170. %K A185056 nonn,hard %O A185056 1,2 %A A185056 _Vaclav Kotesovec_, Dec 22 2011