A325604 Lower left-hand x-coordinate for 3 X 3 invisible forest with 0 < x < y.

1274, 1884, 1924, 1448, 594, 2254, 2364, 2210, 1598, 1000, 2624, 740, 664, 2408, 1924, 1924, 494, 1000, 230, 2914, 650, 1000, 644, 3794, 1924, 3794, 2430, 104, 4146, 3534, 4234, 1748, 2254, 2408, 1274, 1064, 4640, 4520, 2484, 3794

Offset: 1

Author

Benjamin Hutz, May 10 2019

Keywords

• nonn

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).

Examples

			(1274,1308), (1884,2000), (1924,2330), (1448,2714), (594,3128), (2254,2540), (2364,2924), (2210,3080), (1598,3484), (1000,3794)
		

Links

• Benjamin Hutz, Table of n, a(n) for n = 1..1000
• 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.

Crossrefs

Cf. A157426, A157427, A157428, A157429.

Cf. A325602, A325603, A325605, A325606, A325607.