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 A362014 #18 Jan 24 2025 08:48:09 %S A362014 0,0,3,6,18,39,81,141,237,369,561,801,1119,1521,2043,2667,3429,4329, %T A362014 5415,6675,8163,9879,11877,14127,16695,19593,22881,26523,30591,35085, %U A362014 40089,45591,51681,58359,65715,73701,82389,91791,102015,113007,124875 %N A362014 Number of distinct lines passing through exactly two points in a triangular grid of side n. %D A362014 Samuel Dittmer, Hiram Golze, Grant Molnar, and Caleb Stanford, Puzzle and Proof: A Decade of Problems from the Utah Math Olympiad, CRC Press, 2025, p. 34. %F A362014 a(n) = A244504(n) - A234248(n). - _Andrew Howroyd_, Apr 03 2023 %Y A362014 Cf. A234248, A244504 (lines which contain 2 or more points), A050534 (total number of pairs of points). Both are upper bounds. %K A362014 nonn %O A362014 0,3 %A A362014 _Caleb Stanford_, Apr 03 2023