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 A215061 #9 Aug 02 2012 07:55:44
%S A215061 1,0,1,0,0,1,1,0,0,1,0,4,0,0,1,0,0,10,0,0,1,1,0,0,20,0,0,1,0,7,0,0,35,
%T A215061 0,0,1,0,0,28,0,0,56,0,0,1,1,0,0,84,0,0,84,0,0,1,0,10,0,0,210,0,0,120,
%U A215061 0,0,1,0,0,55,0,0,462,0,0,165,0,0,1,1,0,0
%N A215061 Triangle read by rows, e.g.f. exp(x*(z-1/2))*((exp(3*x/2)+2*cos(sqrt(3)*x/2))/3).
%C A215061 Matrix inverse is A215060.
%e A215061 [0] [1]
%e A215061 [1] [0, 1]
%e A215061 [2] [0, 0, 1]
%e A215061 [3] [1, 0, 0, 1]
%e A215061 [4] [0, 4, 0, 0, 1]
%e A215061 [5] [0, 0, 10, 0, 0, 1]
%e A215061 [6] [1, 0, 0, 20, 0, 0, 1]
%e A215061 [7] [0, 7, 0, 0, 35, 0, 0, 1]
%e A215061 [8] [0, 0, 28, 0, 0, 56, 0, 0, 1]
%e A215061 [9] [1, 0, 0, 84, 0, 0, 84, 0, 0, 1]
%o A215061 (Sage)
%o A215061 def A215061_triangle(dim): # See A215060 for function 'triangle'.
%o A215061 var('x, z')
%o A215061 f = exp(x*(z-1/2))*((exp(3*x/2)+2*cos(sqrt(3)*x/2))/3)
%o A215061 return triangle(f, dim)
%o A215061 A215061_triangle(12)
%Y A215061 Cf. A215060, A215062, A215063, A215064, A215065.
%K A215061 nonn,tabl
%O A215061 0,12
%A A215061 _Peter Luschny_, Aug 01 2012