A325607 Lower left-hand y-coordinate for 4 X 4 invisible forest with 0 < x < y.

10199370, 13125369, 13458288, 21374352, 22339875, 29634813, 39738060, 32719728, 42182412, 47211294, 51258282, 53418859, 43209969, 55756413, 48330114, 49362234, 62965329, 52850433, 72584082, 73167345, 73891893, 71088744, 61716444, 66526029, 69342999, 80514873, 71127132

Offset

1,1

Comments

These are 4 X 4 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

Table of n, a(n) for n=1..27.

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

(7247643, 10199370), (6349914, 13125369), (13449225, 13458288), (3268473, 21374352), (16799913, 22339875)

Crossrefs

Cf. A157426, A157427, A157428, A157429.

Cf. A325602, A325603, A325604, A325605, A325606.

Sequence in context: A234404 A034635 A329527 * A282873 A219743 A276510

Adjacent sequences: A325604 A325605 A325606 * A325608 A325609 A325610

Keyword

nonn

Author

Benjamin Hutz, May 31 2019

Extensions

a(6)-a(27) from Giovanni Resta, Jun 05 2019

Status

approved