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 A325605 #18 Jul 14 2019 10:48:58 %S A325605 1308,2000,2330,2714,3128,2540,2924,3080,3484,3794,3730,4654,4730, %T A325605 4234,4640,4718,5300,5564,5654,4928,5704,5654,5718,4598,5654,4640, %U A325605 5642,6200,4640,5150,4598,6094,5984,5984,6408,6460,4674,4794,6104,5620 %N A325605 Lower left-hand y-coordinate for 3 X 3 invisible forest with 0 < x < y. %C A325605 These are 3 X 3 rectangles of lattice points not visible along straight lines of sight from the origin. The sequence is ordered by Euclidean distance from (0,0). %H A325605 E. Goins, P. Harris, B. Kubik, A. Mbirika, <a href="https://arxiv.org/abs/1710.04554">Lattice Point Visibility on Generalized Lines of Sight</a>, arXiv:1710.04554 [math.NT], 2017; Amer. Math. Monthly 125 (2018) 593-601. %H A325605 F. Herzog, B. M. Stewart, <a href="https://www.jstor.org/stable/2317753">Patterns of Visible and Nonvisible Lattice Points</a>, Amer. Math. Monthly 78 (1971) 487-496. %H A325605 S. Laishram, F. Luca, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/Laishram/lai2.html">Rectangles Of Nonvisible Lattice Points</a>, J. Int. Seq. 18 (2015) 15.10.8. %e A325605 1308 is a term because (1274, 1308) is the lower left-hand coordinate of a 3 X 3 invisible forest, i.e., gcd(1274+i, 1308+j) > 1 for 0 <= i <= 2 and 0 <= j <= 2. %e A325605 Other such coordinates are (1884, 2000), (1924, 2330), (1448, 2714), (594, 3128), (2254, 2540), (2364, 2924), (2210, 3080), (1598, 3484), (1000, 3794). %Y A325605 Cf. A157426, A157427, A157428, A157429. %Y A325605 Cf. A325602, A325603, A325604, A325606, A325607. %K A325605 nonn %O A325605 1,1 %A A325605 _Benjamin Hutz_, May 31 2019