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 A371026 #10 Mar 17 2024 18:32:05 %S A371026 1,0,1,0,5,2,0,45,30,6,0,585,510,180,24,0,9945,10350,4950,1200,120,0, %T A371026 208845,247590,144900,48600,9000,720,0,5221125,6855030,4655070, %U A371026 1940400,504000,75600,5040,0,151412625,216093150,164872260,80713080,26334000,5594400,705600,40320 %N A371026 Triangle read by rows: T(n, k) = 4^n*Sum_{j=0..k} (-1)^(k - j)*binomial(k, j)* Pochhammer(j/4, n). %F A371026 T(n, k) = k * T(n-1, k-1) + (4*n - 4 + k) * T(n-1, k) for 0 < k < n with initial values T(n, 0) = 0 for n > 0 and T(n, n) = n! for n >= 0. - _Werner Schulte_, Mar 17 2024 %e A371026 Triangle read by rows: %e A371026 [0] 1; %e A371026 [1] 0, 1; %e A371026 [2] 0, 5, 2; %e A371026 [3] 0, 45, 30, 6; %e A371026 [4] 0, 585, 510, 180, 24; %e A371026 [5] 0, 9945, 10350, 4950, 1200, 120; %e A371026 [6] 0, 208845, 247590, 144900, 48600, 9000, 720; %e A371026 [7] 0, 5221125, 6855030, 4655070, 1940400, 504000, 75600, 5040; %p A371026 A371026 := (n, k) -> local j; 4^n*add((-1)^(k - j)*binomial(k, j)*pochhammer(j/4, n), j = 0..k): seq(seq(A371026(n, k), k = 0..n), n = 0..9); %o A371026 (Python) %o A371026 from functools import cache %o A371026 @cache %o A371026 def T(n, k): # After _Werner Schulte_ %o A371026 if k == 0: return 0**n %o A371026 if k == n: return n * T(n-1, n-1) %o A371026 return k * T(n-1, k-1) + (4*n - 4 + k) * T(n-1, k) %o A371026 for n in range(8): print([T(n, k) for k in range(n + 1)]) %o A371026 # _Peter Luschny_, Mar 17 2024 %Y A371026 Cf. A000142 (main diagonal), A007696 (column 1), A371027 (row sums). %Y A371026 Cf. A371025. %K A371026 nonn,tabl %O A371026 0,5 %A A371026 _Peter Luschny_, Mar 08 2024