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 A341200 #15 Feb 07 2021 00:42:19 %S A341200 1,0,2,0,1,7,0,1,6,34,0,1,8,39,209,0,1,12,63,292,1546,0,1,20,117,544, %T A341200 2505,13327,0,1,36,243,1168,5225,24306,130922,0,1,68,549,2800,12525, %U A341200 55656,263431,1441729,0,1,132,1323,7312,33425,145836,653023,3154824,17572114 %N A341200 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = Sum_{j=0..n} j^k * (n-j)! * binomial(n,j)^2. %F A341200 About e.g.f. of column k, see A105218 or A105219 comment. %e A341200 Square array begins: %e A341200 1, 0, 0, 0, 0, 0, ... %e A341200 2, 1, 1, 1, 1, 1, ... %e A341200 7, 6, 8, 12, 20, 36, ... %e A341200 34, 39, 63, 117, 243, 549, ... %e A341200 209, 292, 544, 1168, 2800, 7312, ... %e A341200 1546, 2505, 5225, 12525, 33425, 97125, ... %t A341200 T[n_, k_] := Sum[If[j == k == 0, 1, j^k] * (n - j)! * Binomial[n, j]^2, {j, 0, n}]; Table[T[k, n - k], {n, 0, 9}, {k, 0, n}] // Flatten (* _Amiram Eldar_, Feb 06 2021 *) %o A341200 (PARI) T(n, k) = sum(j=0, n, j^k*(n-j)!*binomial(n, j)^2); %Y A341200 Columns k=0..4 gives A002720, A103194, A105219, A105218, A341196. %Y A341200 Main diagonal gives A341197. %Y A341200 Cf. A289192. %K A341200 nonn,tabl %O A341200 0,3 %A A341200 _Seiichi Manyama_, Feb 06 2021