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 A279454 #7 Dec 24 2016 09:39:59 %S A279454 2,6,54,1026,38931,2198241,167110761,16248457762,1960813221768 %N A279454 Number of nonequivalent ways to place k>=0 points on an n X n square grid so that no more than 2 points are on a vertical or horizontal straight line. %C A279454 Row sum of triangle A279453. %C A279454 Rotations and reflections of a placement are not counted. For numbers if they are to be counted, see A197458. %Y A279454 Cf. A197458, A279453. %K A279454 nonn,more %O A279454 1,1 %A A279454 _Heinrich Ludwig_, Dec 24 2016