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 A258223 #18 Jun 06 2018 03:08:14 %S A258223 1,1,1,2,8,3,5,69,77,15,14,692,1749,890,105,42,8120,41998,41909,12039, %T A258223 945,132,110278,1114808,1944225,1018865,186594,10395,429,1707965, %U A258223 33058519,94833341,80595226,25798856,3260067,135135,1430,29750636,1093994697,4979407614,6439957299,3201618970,687652446,63390060,2027025 %N A258223 T(n,k) = 1/k! * Sum_{i=0..k} (-1)^(k-i) *C(k,i) * A258222(n,i); triangle T(n,k), n>=0, 0<=k<=n, read by rows. %H A258223 Alois P. Heinz, <a href="/A258223/b258223.txt">Rows n = 0..140, flattened</a> %F A258223 T(n,k) = 1/k! * Sum_{i=0..k} (-1)^(k-i) *C(k,i) * A258222(n,i). %e A258223 Triangle T(n,k) begins: %e A258223 : 1; %e A258223 : 1, 1; %e A258223 : 2, 8, 3; %e A258223 : 5, 69, 77, 15; %e A258223 : 14, 692, 1749, 890, 105; %e A258223 : 42, 8120, 41998, 41909, 12039, 945; %e A258223 : 132, 110278, 1114808, 1944225, 1018865, 186594, 10395; %p A258223 b:= proc(x, y, t, k) option remember; `if`(y>x or y<0, 0, %p A258223 `if`(x=0, 1, b(x-1, y-1, false, k)*`if`(t, (k*x+y)/y, 1) %p A258223 + b(x-1, y+1, true, k) )) %p A258223 end: %p A258223 A:= (n, k)-> b(2*n, 0, false, k): %p A258223 T:= (n, k)-> add(A(n, i)*(-1)^(k-i)*binomial(k, i), i=0..k)/k!: %p A258223 seq(seq(T(n, k), k=0..n), n=0..10); %t A258223 b[x_, y_, t_, k_] := b[x, y, t, k] = If[y > x || y < 0, 0, If[x == 0, 1, b[x-1, y-1, False, k]*If[t, (k*x + y)/y, 1] + b[x-1, y+1, True, k]]]; %t A258223 A[n_, k_] := b[2*n, 0, False, k]; %t A258223 T[n_, k_] := Sum[A[n, i]*(-1)^(k - i)*Binomial[k, i], {i, 0, k}]/k!; %t A258223 Table[T[n, k], {n, 0, 10}, { k, 0, n}] // Flatten (* _Jean-François Alcover_, Jun 06 2018, from Maple *) %Y A258223 Column k=0 gives A000108. %Y A258223 Main diagonal gives A001147. %Y A258223 Row sums give A258224. %Y A258223 T(2n,n) gives A292695. %Y A258223 Cf. A258220, A258222. %K A258223 nonn,tabl %O A258223 0,4 %A A258223 _Alois P. Heinz_, May 23 2015