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.
%I A003833 #19 Jul 14 2025 09:59:45
%S A003833 20,1,18,4,13,6,10,15,2,17,3,19,7,16,8,11,14,9,12,5,20,1,18,4,13,6,10,
%T A003833 15,2,17,3,19,7,16,8,11,14,9,12,5,20,1,18,4,13,6,10,15,2,17,3,19,7,16,
%U A003833 8,11,14,9,12,5,20,1,18,4,13,6,10,15,2,17,3,19,7,16,8,11,14,9
%N A003833 Sectors around outside of dartboard.
%C A003833 Known as the standard, London or clock dartboard.
%C A003833 Periodic with period 20. - _Paolo Xausa_, Jul 14 2025
%D A003833 Marilyn vos Savant, "Ask Marilyn," in 'Parade, The Sunday Newspaper Magazine,' page 12, Sunday, Jan 12, 2003.
%H A003833 Paolo Xausa, <a href="/A003833/b003833.txt">Table of n, a(n) for n = 1..10000</a>
%H A003833 K. S. Brown, <a href="http://www.mathpages.com/home/kmath025.htm">The Dartboard Sequence</a>
%H A003833 American Darts Organization, <a href="http://www.adodarts.com/">Home page</a>
%H A003833 World Darts Federation, <a href="http://www.dartswdf.com/Rules/PlayRls/Playrule.html">WDF Playing and Tournament Rules</a>
%H A003833 <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1).
%t A003833 PadRight[{}, 100, {20, 1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5}] (* _Paolo Xausa_, Jul 14 2025 *)
%Y A003833 Cf. A008575, A104159.
%K A003833 nonn,easy
%O A003833 1,1
%A A003833 _N. J. A. Sloane_