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 A241794 #7 Apr 28 2014 19:00:24 %S A241794 1,5,16,43,99,215,430,834,1529,2765,4792,8216,13684,22575,36402,58285, %T A241794 91617,143097,220317,337100,509718,766655,1141457,1690994,2484138, %U A241794 3631902,5271297,7617750,10937657,15640771,22240250,31502316,44396662,62345539,87149572 %N A241794 Number of ballot sequences of length n having exactly one descent. %e A241794 a(3) = 1: [1,2,1]. %e A241794 a(4) = 5: [1,1,2,1], [1,2,1,1], [1,2,1,2], [1,2,1,3], [1,2,3,1]. %Y A241794 Column k=1 of A238121 and of A238122. %K A241794 nonn %O A241794 3,2 %A A241794 _Joerg Arndt_ and _Alois P. Heinz_, Apr 28 2014