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 A370418 #10 Mar 05 2024 11:25:06 %S A370418 1,1,2,4,6,24,36,48,120,720,576,720,1440,5040,40320,14400,17280,30240, %T A370418 80640,362880,3628800,518400,604800,967680,2177280,7257600,39916800, %U A370418 479001600,25401600,29030400,43545600,87091200,239500800,958003200,6227020800,87178291200 %N A370418 Triangle read by rows. T(n, k) = (n - k)! * (n + k)!. %F A370418 Sum_{k=0..n} (-1)^k*T(n, k) = n!^2 / 2 + (-1)^n * (2*n + 2)! / (2*n + 2)^2. %e A370418 Triangle starts: %e A370418 [0] 1; %e A370418 [1] 1, 2; %e A370418 [2] 4, 6, 24; %e A370418 [3] 36, 48, 120, 720; %e A370418 [4] 576, 720, 1440, 5040, 40320; %e A370418 [5] 14400, 17280, 30240, 80640, 362880, 3628800; %e A370418 [6] 518400, 604800, 967680, 2177280, 7257600, 39916800, 479001600; %p A370418 T := (n, k) -> (n - k)! * (n + k)!: %p A370418 seq(seq(T(n, k), k = 0..n), n = 0..7); %t A370418 Table[(n - k)!*(n + k)!, {n, 0, 7}, {k, 0, n}] // Flatten (* _Michael De Vlieger_, Mar 05 2024 *) %Y A370418 Cf. A010050 (main diagonal), A009445 (subdiagonal), A001044 (column 0), A175430 (column 1), A024420 (bisection is alternating sum). %Y A370418 Cf. A119502, A143084. %K A370418 nonn,tabl %O A370418 0,3 %A A370418 _Peter Luschny_, Feb 27 2024