A076119 Every second sector of a dartboard, starting at the top (20) and working around clockwise.

20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2, 3, 7, 8, 14, 12, 20, 18, 13, 10, 2

Offset: 1

Author

Darren Izzard (zysyshelp(AT)yahoo.com), Oct 31 2002

Keywords

• nonn
• easy

Comments

Period 10: repeat [20,18,13,10,2,3,7,8,14,12]. - Wesley Ivan Hurt, Jul 15 2015

Links

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

Crossrefs

Cf. A003833.

Programs

Magma

R:=[20,18,13,10,2,3,7,8,14,12]; [n le 10 select R[n] else Self(n-10): n in [1..100]]; // Wesley Ivan Hurt, Jul 15 2015

Magma

&cat [[20, 18, 13, 10, 2, 3, 7, 8, 14, 12]: n in [1..7]]; // Vincenzo Librandi, Jul 16 2015

Maple

A076119:=n->[20,18,13,10,2,3,7,8,14,12][(n mod 10)+1]: seq(A076119(n), n=0..100); # Wesley Ivan Hurt, Jul 15 2015

Mathematica

CoefficientList[Series[(20 + 18 x + 13 x^2 + 10 x^3 + 2 x^4 + 3 x^5 + 7 x^6 + 8 x^7 + 14 x^8 + 12 x^9)/(1 - x^10), {x, 0, 100}], x] (* Wesley Ivan Hurt, Jul 15 2015 *)

PARI

a(n)=[12,20,18,13,10,2,3,7,8,14][n%10+1] \\ Charles R Greathouse IV, Aug 20 2015

Formula

G.f.: x*(20+18*x+13*x^2+10*x^3+2*x^4+3*x^5+7*x^6+8*x^7+14*x^8+12*x^9) / (1-x^10). a(n) = a(n-10), n>10. - Wesley Ivan Hurt, Jul 15 2015