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 A371767 #6 Apr 14 2024 11:51:19 %S A371767 1,1,1,1,2,4,1,3,12,36,1,4,24,144,576,1,5,40,360,2880,14400,1,6,60, %T A371767 720,8640,86400,518400,1,7,84,1260,20160,302400,3628800,25401600,1,8, %U A371767 112,2016,40320,806400,14515200,203212800,1625702400 %N A371767 Triangle read by rows: T(n, k) = (k! * n!)/(n - k)!. %e A371767 Triangle starts: %e A371767 [0] 1; %e A371767 [1] 1, 1; %e A371767 [2] 1, 2, 4; %e A371767 [3] 1, 3, 12, 36; %e A371767 [4] 1, 4, 24, 144, 576; %e A371767 [5] 1, 5, 40, 360, 2880, 14400; %e A371767 [6] 1, 6, 60, 720, 8640, 86400, 518400; %e A371767 [7] 1, 7, 84, 1260, 20160, 302400, 3628800, 25401600; %p A371767 T := (n, k) -> (k! * n!)/(n - k)!: %p A371767 for n from 0 to 6 do seq(T(n, k), k = 0..n) od; %Y A371767 Cf. A000142, A001044 (main diagonal), A010790 (subdiagonal), A046662 (row sums), A089041 (alternating row sums), A010050 (central terms). %K A371767 nonn,tabl %O A371767 0,5 %A A371767 _Peter Luschny_, Apr 14 2024