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 A018813 #13 Nov 27 2017 03:18:47 %S A018813 0,0,0,0,0,0,14,4,4,4,4,28,60,44,20,20,88,172,272,228,168,180,284,404, %T A018813 540,484,628,788,964,1276,1620,1612,1588,1548,1492,1420,2072,2484, %U A018813 2928,3404,3912,4788,5728,5852,5960,6052,6692,7364,8068,8004,8520,9468,10464 %N A018813 Number of lines through exactly 6 points of an n X n grid of points. %H A018813 Seiichi Manyama, <a href="/A018813/b018813.txt">Table of n, a(n) for n = 0..1000</a> %H A018813 S. Mustonen, <a href="http://www.survo.fi/papers/PointsInGrid.pdf">On lines and their intersection points in a rectangular grid of points</a> %K A018813 nonn %O A018813 0,7 %A A018813 _David W. Wilson_