cp's OEIS Frontend

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.

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A346784 Numerators of minimal squared radii of circular disks covering a record number of lattice points of the hexagonal lattice, when the centers of the circles are chosen to maximize the number of covered lattice points.

Original entry on oeis.org

0, 1, 1, 3, 1, 7, 49, 9, 7, 13, 169, 91, 4, 133, 21, 361, 1729, 169, 19, 7, 961, 133, 9, 39, 21793, 481, 31, 9331, 301, 3367, 49, 817, 13, 361, 931, 1813, 63, 16
Offset: 1

Views

Author

Hugo Pfoertner, Aug 08 2021

Keywords

Comments

It is conjectured that the number of covered grid points is given by A346126(n-1) for n>2.

Examples

			0, 1/4, 1/3, 3/4, 1, 7/4, 49/25, 9/4, 7/3, 13/4, 169/48, 91/25, 4, 133/27, 21/4, 361/64, 1729/289, 169/27, 19/3, 7, 961/121, 133/16, 9, 39/4, 21793/2187, ...
.
     Diameter  Covered      R^2 =
     of disk   grid        (D/2)^2 =
   n    D      points    a(n) / A346785(n)
.
   1 0.00000     1        0   /    1
   2 1.00000     2        1   /    4
   3 1.15470     3        1   /    3
   4 1.73205     4        3   /    4
   5 2.00000     7        1   /    1
   6 2.64575     8        7   /    4
   7 2.80000     9       49   /   25
   8 3.00000    10        9   /    4
   9 3.05505    12        7   /    3
  10 3.60555    14       13   /    4
		

Crossrefs

Corresponding denominators are A346785.

A346785 Denominators of minimal squared radii of circular disks covering a record number of lattice points of the hexagonal lattice, when the centers of the circles are chosen to maximize the number of covered lattice points.

Original entry on oeis.org

1, 4, 3, 4, 1, 4, 25, 4, 3, 4, 48, 25, 1, 27, 4, 64, 289, 27, 3, 1, 121, 16, 1, 4, 2187, 48, 3, 841, 27, 289, 4, 64, 1, 25, 64, 121, 4, 1
Offset: 1

Views

Author

Hugo Pfoertner, Aug 08 2021

Keywords

Examples

			0, 1/4, 1/3, 3/4, 1, 7/4, 49/25, 9/4, 7/3, 13/4, 169/48, 91/25, 4, 133/27, 21/4, 361/64, 1729/289, 169/27, 19/3, 7, 961/121, 133/16, 9, ...
		

Crossrefs

Corresponding numerators are A346784.
Showing 1-2 of 2 results.