A125851 Number of points in a hexagonal lattice covered by a circular disk of diameter n if the center of the circle is chosen such that the disk covers the minimum possible number of lattice points.

0, 3, 6, 12, 19, 30, 40, 54, 69, 87, 102, 123, 149, 174, 198, 225, 253, 287, 313, 354, 396, 435

Offset: 1

Author

Hugo Pfoertner, Jan 07 2007, Feb 11 2007

Keywords

• more
• nonn

Comments

a(n)<=min(A053416(n),A053479(n),A053417(n))

Links

• Index entries for sequences related to A2 = hexagonal = triangular lattice
• Hugo Pfoertner, Minimal number of points in the hexagonal lattice covered by circular disks. Illustrations.

Crossrefs

Cf. A053416, A053479, A053417, A125852. The corresponding sequences for the square lattice and the honeycomb net are A123689 and A127405, respectively.