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 A258310 #12 May 01 2022 13:37:15 %S A258310 1,1,2,1,4,3,9,14,3,21,50,15,51,204,122,15,127,784,644,105,323,3212, %T A258310 4115,1310,105,835,13068,22587,9270,945,2188,55475,137503,85109,16764, %U A258310 945,5798,238073,787127,614779,149754,10395 %N A258310 T(n,k) = 1/k! * Sum_{i=0..k} (-1)^(k-i) *C(k,i) * A258309(n,i); triangle T(n,k), n>=0, 0<=k<=floor(n/2), read by rows. %H A258310 Alois P. Heinz, <a href="/A258310/b258310.txt">Rows n = 0..200, flattened</a> %e A258310 Triangle T(n,k) begins: %e A258310 : 1; %e A258310 : 1; %e A258310 : 2, 1; %e A258310 : 4, 3; %e A258310 : 9, 14, 3; %e A258310 : 21, 50, 15; %e A258310 : 51, 204, 122, 15; %e A258310 : 127, 784, 644, 105; %e A258310 : 323, 3212, 4115, 1310, 105; %e A258310 : 835, 13068, 22587, 9270, 945; %e A258310 : 2188, 55475, 137503, 85109, 16764, 945; %p A258310 b:= proc(x, y, t, k) option remember; `if`(y>x or y<0, 0, %p A258310 `if`(x=0, 1, b(x-1, y-1, false, k)*`if`(t, (k*x+y)/y, 1) %p A258310 +b(x-1, y, false, k) +b(x-1, y+1, true, k))) %p A258310 end: %p A258310 A:= (n, k)-> b(n, 0, false, k): %p A258310 T:= proc(n, k) option remember; %p A258310 add(A(n, i)*(-1)^(k-i)*binomial(k, i), i=0..k)/k! %p A258310 end: %p A258310 seq(seq(T(n, k), k=0..n/2), n=0..14); %t A258310 b[x_, y_, t_, k_] := b[x, y, t, k] = If[y > x || y < 0, 0, %t A258310 If[x == 0, 1, b[x - 1, y - 1, False, k]*If[t, (k*x + y)/y, 1] %t A258310 + b[x - 1, y, False, k] + b[x - 1, y + 1, True, k]]]; %t A258310 A[n_, k_] := b[n, 0, False, k]; %t A258310 T[n_, k_] := Sum[A[n, i] (-1)^(k - i) Binomial[k, i], {i, 0, k}]/k!; %t A258310 Table[Table[T[n, k], {k, 0, n/2}], {n, 0, 14}] // Flatten (* _Jean-François Alcover_, May 01 2022, after _Alois P. Heinz_ *) %Y A258310 Column k=0 gives A001006. %Y A258310 T(2n,n) gives A001147. %Y A258310 Row sums give A258311. %Y A258310 Cf. A258307, A258309. %K A258310 nonn,tabf %O A258310 0,3 %A A258310 _Alois P. Heinz_, May 25 2015