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 A167213 #11 Jun 05 2016 23:49:21
%S A167213 1,1,3,7,17,40,98,233,562,1349,3243,7789,18722,44978,108083,259700,
%T A167213 624027,1499427,3602913,8657216,20801982,49983920,120103675,288590527,
%U A167213 693438537,1666225599,4003682857,9620231375,23115930197,55544009564
%N A167213 The number of ordered ways to achieve a score of n in darts.
%C A167213 The game of darts has unmodified scores (1, 2, ..., 20), doubles of those values (2, 4, ..., 40), triples of those values (3, 6, ..., 60), and bull's eye values of 25 and 50.
%H A167213 G. C. Greubel, <a href="/A167213/b167213.txt">Table of n, a(n) for n = 0..1000</a>
%F A167213 G.f. = 1/(1-(x*(1-x^20)/(1-x)+x^2*(1-x^40)/(1-x^2)+x^3*(1-x^60)/(1-x^3)+x^25+x^50)).
%e A167213 There are 7 ordered ways to get a total score of 3: (#1) "1","1","1"; (#2) "2","1"; (#3) "1","2"; (#4) "double 1","1" (#5) "1","double 1"; (#6) "triple 1"; and (#7) "3".
%t A167213 CoefficientList[Series[1/(1-(x (1-x^20)/(1-x)+x^2(1-x^40)/(1-x^2)+ x^3(1- x^60)/ (1-x^3)+x^25+x^50)),{x,0,30}],x] (* _Harvey P. Dale_, Jul 04 2011 *)
%K A167213 easy,nonn
%O A167213 0,3
%A A167213 _Lee A. Newberg_, Oct 30 2009