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 A337722 #15 Sep 20 2020 01:54:32 %S A337722 1,4,9,16,24,34,44,58,73 %N A337722 Maximum number of knights within an n X n chessboard, where each knight has a path off the board. %C A337722 Given an n X n chessboard, this sequence is the maximum number of knights that can be placed on the board, such that each knight has a free path to jump "off" the board without another knight moving. %C A337722 An example for a(3): %C A337722 XXX %C A337722 XXX %C A337722 XXX %C A337722 Here, all knights can jump off the board via knight movement. The middle knight is not blocked by any pieces. %C A337722 An example for a(5): %C A337722 XXXXX %C A337722 XXXXX %C A337722 XX-XX %C A337722 XXXXX %C A337722 XXXXX %C A337722 Here, a knight can occupy all spaces except the central space, where a knight would not be able to jump off the board and would not be able to jump to another free square. %H A337722 Nicholas Tran, <a href="https://github.com/NicholasACTran/chess-packing">Solution in ASP</a> %Y A337722 Cf. A337746 (bishops), A335445 (rooks). %K A337722 nonn,hard,more %O A337722 1,2 %A A337722 _Nicholas Tran_, Sep 17 2020