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 A193846 #16 Feb 18 2024 14:41:34 %S A193846 2,4,8,8,28,26,16,80,136,80,32,208,512,568,242,64,512,1648,2672,2188, %T A193846 728,128,1216,4832,10288,12392,8020,2186,256,2816,13312,35072,55648, %U A193846 53216,28432,6560,512,6400,35072,110080,216512,273376,216512,98416 %N A193846 Triangular array: the fission of ((x+2)^n) by ((x+1)^n). %C A193846 See A193842 for the definition of fission of two sequences of polynomials or triangular arrays. %H A193846 Andrew Howroyd, <a href="/A193846/b193846.txt">Table of n, a(n) for n = 0..1325</a> (rows 0..50) %F A193846 G.f.: A(x,y) = 2/(1 - 2*(1 + 2*y)*x + y*(2 + 3*y)*x^2). - _Andrew Howroyd_, Feb 18 2024 %e A193846 First six rows: %e A193846 2 %e A193846 4....8 %e A193846 8....28....26 %e A193846 16...80....136....80 %e A193846 32...208...512....568....242 %e A193846 64...512...1648...2672...2188...728 %t A193846 p[n_, x_] := (x + 2)^n; %t A193846 q[n_, x_] := (x + 1)^n %t A193846 p1[n_, k_] := Coefficient[p[n, x], x^k]; %t A193846 p1[n_, 0] := p[n, x] /. x -> 0; %t A193846 d[n_, x_] := Sum[p1[n, k]*q[n - 1 - k, x], {k, 0, n - 1}] %t A193846 h[n_] := CoefficientList[d[n, x], {x}] %t A193846 TableForm[Table[Reverse[h[n]], {n, 0, z}]] %t A193846 Flatten[Table[Reverse[h[n]], {n, -1, z}]] (* A193846 *) %t A193846 TableForm[Table[h[n], {n, 0, z}]] %t A193846 Flatten[Table[h[n], {n, -1, z}]] (* A193847 *) %t A193846 TableForm[Table[Reverse[h[n]/2], {n, 0, z}]] %t A193846 Flatten[Table[Reverse[h[n]]/2, {n, -1, z}]] (* A193848 *) %t A193846 TableForm[Table[h[n]/2, {n, 0, z}]] %t A193846 Flatten[Table[h[n]/2, {n, -1, z}]] (* A193849 *) %o A193846 (PARI) T(n)={[2*Vecrev(p) | p<-Vec(1/(1 - 2*(1 + 2*y)*x + y*(2 + 3*y)*x^2) + O(x*x^n))]} %o A193846 { my(A=T(10)); for(i=1, #A, print(A[i])) } \\ _Andrew Howroyd_, Feb 18 2024 %Y A193846 Cf. A193842, A193847, A193848. %K A193846 nonn,tabl %O A193846 0,1 %A A193846 _Clark Kimberling_, Aug 07 2011