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 A193738 #8 May 11 2013 18:13:24 %S A193738 1,1,1,1,2,2,1,2,3,3,1,2,3,4,4,1,2,3,4,5,5,1,2,3,4,5,6,6,1,2,3,4,5,6, %T A193738 7,7,1,2,3,4,5,6,7,8,8,1,2,3,4,5,6,7,8,9,9,1,2,3,4,5,6,7,8,9,10,10,1, %U A193738 2,3,4,5,6,7,8,9,10,11,11,1,2,3,4,5,6,7,8,9,10,11,12,12,1,2,3,4 %N A193738 Triangular array: the fusion of polynomial sequences P and Q given by p(n,x)=q(n,x)=x^n+x^(n-1)+...+x+1. %C A193738 See A193722 for the definition of fusion of two sequences of polynomials or triangular arrays. %H A193738 Reinhard Zumkeller, <a href="/A193738/b193738.txt">Rows n = 0..100 of triangle, flattened</a> %e A193738 First six rows: %e A193738 1 %e A193738 1....1 %e A193738 1....2....2 %e A193738 1....2....3....3 %e A193738 1....2....3....4...4 %e A193738 1....2....3....4...5...5 %t A193738 z = 12; %t A193738 p[0, x_] := 1 %t A193738 p[n_, x_] := x*p[n - 1, x] + 1; p[n_, 0] := p[n, x] /. x -> 0 %t A193738 q[n_, x_] := p[n, x] %t A193738 t[n_, k_] := Coefficient[p[n, x], x^(n - k)]; %t A193738 t[n_, n_] := p[n, x] /. x -> 0; %t A193738 w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1 %t A193738 g[n_] := CoefficientList[w[n, x], {x}] %t A193738 TableForm[Table[Reverse[g[n]], {n, -1, z}]] %t A193738 Flatten[Table[Reverse[g[n]], {n, -1, z}]] (* A193738 *) %t A193738 TableForm[Table[g[n], {n, -1, z}]] %t A193738 Flatten[Table[g[n], {n, -1, z}]] (* A193739 *) %o A193738 (Haskell) %o A193738 a193738 n k = a193738_tabl !! n !! k %o A193738 a193738_row n = a193738_tabl !! n %o A193738 a193738_tabl = map reverse a193739_tabl %o A193738 -- _Reinhard Zumkeller_, May 11 2013 %Y A193738 Cf. A193722, A193739. %K A193738 nonn,tabl %O A193738 0,5 %A A193738 _Clark Kimberling_, Aug 04 2011