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 A241626 #15 Feb 06 2015 08:10:58
%S A241626 1,3,9,19,41,77,142,247,421,689,1113,1750,2712,4128,6208,9201,13502,
%T A241626 19585,28158,40109,56689,79486,110703,153129,210536,287752,391172,
%U A241626 528961,711837,953429,1271421,1688293,2232899,2941798,3861621,5051174,6584958,8556655
%N A241626 Number of compositions of n with exactly one descent.
%H A241626 Joerg Arndt, Alois P. Heinz and Vaclav Kotesovec, <a href="/A241626/b241626.txt">Table of n, a(n) for n = 3..4000</a> (first 1000 terms from Joerg Arndt and Alois P. Heinz)
%e A241626 a(3) = 1: [2,1].
%e A241626 a(4) = 3: [3,1], [1,2,1], [2,1,1].
%e A241626 a(5) = 9: [3,2], [4,1], [2,1,2], [3,1,1], [1,3,1], [2,2,1], [2,1,1,1], [1,1,2,1], [1,2,1,1].
%p A241626 b:= proc(n, i) option remember;
%p A241626 `if`(n=0, 1, convert(series(add(b(n-j, j)*
%p A241626 `if`(j<i, x, 1), j=1..n), x, 2), polynom))
%p A241626 end:
%p A241626 a:= n-> coeff(b(n, 0), x, 1):
%p A241626 seq(a(n), n=3..50);
%t A241626 b[n_, i_] := b[n, i] = If[n == 0, 1, Normal[Series[Sum[b[n - j, j]* If[j < i, x, 1], {j, 1, n}], {x, 0, 2}]]]; a[n_] := Coefficient[b[n, 0], x, 1]; Table[a[n], {n, 3, 50}] (* _Jean-François Alcover_, Feb 06 2015, after Maple *)
%Y A241626 Column k=1 of A238343 and of A238344.
%K A241626 nonn
%O A241626 3,2
%A A241626 _Joerg Arndt_ and _Alois P. Heinz_, Apr 26 2014