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 A325605 Lower left-hand y-coordinate for 3 X 3 invisible forest with 0 < x < y. 8
 1308, 2000, 2330, 2714, 3128, 2540, 2924, 3080, 3484, 3794, 3730, 4654, 4730, 4234, 4640, 4718, 5300, 5564, 5654, 4928, 5704, 5654, 5718, 4598, 5654, 4640, 5642, 6200, 4640, 5150, 4598, 6094, 5984, 5984, 6408, 6460, 4674, 4794, 6104, 5620 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 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). LINKS E. Goins, P. Harris, B. Kubik, A. Mbirika, Lattice Point Visibility on Generalized Lines of Sight, arXiv:1710.04554 [math.NT], 2017; Amer. Math. Monthly 125 (2018) 593-601. F. Herzog, B. M. Stewart, Patterns of Visible and Nonvisible Lattice Points, Amer. Math. Monthly 78 (1971) 487-496. S. Laishram, F. Luca, Rectangles Of Nonvisible Lattice Points, J. Int. Seq. 18 (2015) 15.10.8. EXAMPLE 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. Other such coordinates are (1884, 2000), (1924, 2330), (1448, 2714), (594, 3128), (2254, 2540), (2364, 2924), (2210, 3080), (1598, 3484), (1000, 3794). CROSSREFS Cf. A157426, A157427, A157428, A157429. Cf. A325602, A325603, A325604, A325606, A325607. Sequence in context: A255025 A126841 A106815 * A281211 A233975 A209853 Adjacent sequences:  A325602 A325603 A325604 * A325606 A325607 A325608 KEYWORD nonn AUTHOR Benjamin Hutz, May 31 2019 STATUS approved

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Last modified December 3 05:05 EST 2021. Contains 349445 sequences. (Running on oeis4.)