A244512 The angle of the center of each numbered sector of a standard competition dartboard.

288, 54, 90, 324, 252, 0, 126, 162, 216, 18, 180, 234, 342, 198, 36, 144, 72, 306, 108, 270

Offset

1,1

Comments

A standard dartboard is divided into 20 sectors each subtending an angle of 18 degrees.

The sequence is generated by considering the positive x-axis to be running through the center of the sector numbered "6" and defining this to be 0 degrees. The angular position of each sector is then defined relative to this position through a clockwise rotation of a line collinear with x until the line divides the sector of interest. The numbers are then sectors are ordered from 1 to 20 generating the full sequence.

It is a mere formality to fully define the bounds of each sector by adding and subtracting 9 degrees from each of the numbers in the sequence.

Links

Table of n, a(n) for n=1..20.

Wikipedia, Darts

Formula

n = A003833(a(n)/18+6). - Jens Kruse Andersen, Jul 19 2014

Crossrefs

Cf. A003833, A008575.

Sequence in context: A011817 A334008 A035882 * A214301 A296902 A371948

Adjacent sequences: A244509 A244510 A244511 * A244513 A244514 A244515

Keyword

nonn,fini,full

Author

Philip Mizzi, Jun 29 2014

Extensions

Incorrect term removed by Jens Kruse Andersen, Jul 19 2014

Status

approved