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 A331780 #6 Feb 10 2020 11:08:27 %S A331780 0,0,3,10,31,70,153,268,469,746,1153,1648,2361,3230,4415,5784,7473, %T A331780 9450,11963,14772,18255,22194,26793,31824,37837,44474,52187,60516, %U A331780 69983,80318,92233,104972,119525,135294,152739,171240,191685,213510,237915,263640 %N A331780 One-half of the number of lines through at least 2 points of an n X n grid of points. %H A331780 M. A. Alekseyev, M. Basova, N. Yu. Zolotykh. <a href="http://dx.doi.org/10.1137/140978090">On the minimal teaching sets of two-dimensional threshold functions</a>. SIAM J. Disc. Math. 29(1), 2015, pp. 157-165. %Y A331780 Equals A018808/2. %K A331780 nonn %O A331780 0,3 %A A331780 _N. J. A. Sloane_, Feb 10 2020