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 A158524 #10 Jan 28 2018 02:46:05 %S A158524 1,1,1,2,2,2,6,3,3,6,18,4,4,8,18,52,5,5,10,24,52,148,6,6,12,30,70,148, %T A158524 420,7,7,14,36,88,200,420,1192,8,8,16,42,106,252,568,1192,3384,9,9,18, %U A158524 48,124,304,716,1612,3384,9608,10,10,20,54,142,356,864,2032,4576,9608 %N A158524 Choulet-Curtz triangle with T(0,0)=1, T(n,n)=T(n,0). %C A158524 Row sums are in A078484. %C A158524 This sequence is an example of a sequence u(n) which satisfies (using the notation from the link): T_{1,1}(u(0), u(1), u(2), u(3), ...) = (u(1), u(2), u(3), ...). The o.g.f of all such sequences is given by the formula Phi(z)=u(0)*((1-3*z+2*z^2-z^3)/(1-4*z+4*z^2-2*z^3))+((z+z^3)/(1-4*z+4*z^2-2*z^3)) with u(0) in N or Z; the sequences are given by u(n) = u(0)*(1, 1, 2, 5, 14, 40, 114, 324, 920, ...) + (0, 1, 4, 13, 38, 108, 868, 2464, 6996, ...), i.e., u(n) = u(0)*A159035(n) + A159036(n). - _Richard Choulet_, Apr 03 2009 %H A158524 Richard Choulet, <a href="http://www.apmep.fr/IMG/pdf/curtz1.pdf">Curtz-like transformation</a>. %F A158524 T(n,k) = T(n-1,k) + T(k-1,k-1), k >= 1, n > k; %F A158524 T(n,n) = T(n,0) = Sum_{k=0..n} T(n-1,k); T(0,0)=1. %e A158524 Triangle begins %e A158524 1; %e A158524 1, 1; %e A158524 2, 2, 2; %e A158524 6, 3, 3, 6; %e A158524 18, 4, 4, 8, 18; %e A158524 52, 5, 5, 10, 24, 52; %e A158524 148, 6, 6, 12, 30, 70, 148; %Y A158524 Cf. A078484. %Y A158524 Cf. A159035, A159036. - _Richard Choulet_, Apr 03 2009 %K A158524 nonn,tabl %O A158524 0,4 %A A158524 _Philippe Deléham_, Mar 20 2009