A244147 Number of hexagons (side length 1) that intersect the circumference of a circle of radius n centered at a lattice point.

3, 9, 12, 15, 21, 24, 27, 39, 42, 39, 51, 54, 51, 63, 66, 69, 81, 78, 75, 99, 96, 93, 105, 114, 105, 123, 120, 117, 141, 138, 129, 147, 156, 153, 159, 162, 159, 177, 180, 171, 201, 192, 183, 201, 204, 201, 219, 216, 207, 237, 240, 225, 249, 258, 243, 267, 246, 261, 285, 276

Offset

1,1

Comments

The pattern repeats itself at every 2*Pi/3 sector along the circumference. The hexagon count per one-third sector by rows can be arranged as an irregular triangle. The double hexagons in a row are symmetrically placed. See illustration.

Links

Table of n, a(n) for n=1..60.

Kival Ngaokrajang, Illustration of initial terms

Kival Ngaokrajang, Small Basic program

Prog

(Small Basic) ' See links.

Crossrefs

Cf. A242118, A242394, A242395.

Sequence in context: A138921 A194412 A136290 * A103531 A333441 A108860

Adjacent sequences: A244144 A244145 A244146 * A244148 A244149 A244150

Keyword

nonn

Author

Kival Ngaokrajang, Jun 21 2014

Status

approved