A104158 Numbers on a standard, London, or clock dartboard read in a counterclockwise direction.

20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1, 20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1, 20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1, 20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6

Offset

0,1

Comments

Sequence is periodic with period 20. - Michel Marcus, Jul 26 2013

References

GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 82.

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

K. S. Brown, The Dartboard Sequence

Patrick Chaplin, Why are the numbers on a dartboard in the order they are?

Sven Silow, Why this particular numbering scheme?

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1).

Mathematica

PadRight[{}, 100, {20, 5, 12, 9, 14, 11, 8, 16, 7, 19, 3, 17, 2, 15, 10, 6, 13, 4, 18, 1}] (* Paolo Xausa, Jul 17 2025 *)

Crossrefs

Cf. A003833, A008575.

Sequence in context: A385172 A040386 A309321 * A068612 A233820 A040387

Adjacent sequences: A104155 A104156 A104157 * A104159 A104160 A104161

Keyword

nonn,easy

Author

Andrew G. West (WestA(AT)wlu.edu), Mar 09 2005

Status

approved