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 A193822 #6 Mar 30 2012 18:57:38 %S A193822 1,1,1,3,3,2,9,9,8,4,27,27,26,20,8,81,81,80,72,48,16,243,243,242,232, %T A193822 192,112,32,729,729,728,716,656,496,256,64,2187,2187,2186,2172,2088, %U A193822 1808,1248,576,128,6561,6561,6560,6544,6432,5984,4864,3072,1280,256 %N A193822 Mirror of the triangle A193821. %C A193822 A193822 is obtained by reversing the rows of the triangle A193821. %F A193822 Write w(n,k) for the triangle at A193821. The triangle at A193822 is then given by w(n,n-k). %e A193822 First six rows: %e A193822 1 %e A193822 1....1 %e A193822 3....3....2 %e A193822 9....9....8.....4 %e A193822 27...27...26....20...8 %e A193822 81...81...80....72...48...16 %t A193822 p[n_, x_] := (a*x + b)^n %t A193822 q[0, x_] := 1 %t A193822 q[n_, x_] := x*q[n - 1, x] + 1; q[n_, 0] := q[n, x] /. x -> 0; %t A193822 t[n_, k_] := Coefficient[p[n, x], x^k]; t[n_, 0] := p[n, x] /. x -> 0; %t A193822 w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1 %t A193822 g[n_] := CoefficientList[w[n, x], {x}] %t A193822 TableForm[Table[Reverse[g[n]], {n, -1, z}]] %t A193822 Flatten[Table[Reverse[g[n]], {n, -1, z}]] (* A193821 *) %t A193822 TableForm[Table[g[n], {n, -1, z}]] %t A193822 Flatten[Table[g[n], {n, -1, z}]] (* A193822 *) %Y A193822 Cf. A193722, A193821. %K A193822 nonn,tabl %O A193822 0,4 %A A193822 _Clark Kimberling_, Aug 06 2011