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 A241798 #6 Apr 28 2014 19:02:10 %S A241798 4,112,1615,15403,112106,672015,3477691,16037089,67235292,260887532, %T A241798 946435074,3246205986,10587385911,33085654876,99411959668, %U A241798 288773319190,812777159786,2225529375130,5937743304924,15483111029378,39503358108034,98849770060367,242801184657314 %N A241798 Number of ballot sequences of length n having exactly five descents. %e A241798 a(9) = 4: [1,2,1,3,2,1,3,2,1], [1,2,1,3,2,1,4,2,1], [1,2,1,3,2,1,4,3,1], [1,2,1,3,2,1,4,3,2]. %Y A241798 Column k=5 of A238121 and of A238122. %K A241798 nonn %O A241798 9,1 %A A241798 _Joerg Arndt_ and _Alois P. Heinz_, Apr 28 2014