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 A158868 #9 Mar 08 2022 03:47:06 %S A158868 1,5,2,14,7,6,126,54,54,24,594,297,264,132,120,7722,3432,3432,1560, %T A158868 1560,720,51480,25740,23400,11700,10800,5400,5040,875160,397800, %U A158868 397800,183600,183600,85680,85680,40320,7558200,3779100,3488400,1744200,1627920,813960,766080,383040,362880 %N A158868 Triangle T(n, k) = (2*n+1)!! * 2^(floor((n-1)/2) + floor(k/2) + 1) * Beta(floor(n/2) + floor((k-1)/2) + 2, floor((n-1)/2) + floor(k/2) + 2), read by rows. %H A158868 G. C. Greubel, <a href="/A158868/b158868.txt">Rows n = 1..50 of the triangle, flattened</a> %F A158868 T(n, k) = (2*n+1)!! * 2^(floor((n-1)/2) + floor(k/2) + 1) * Beta(floor(n/2) + floor((k-1)/2) + 2, floor((n-1)/2) + floor(k/2) + 2). %F A158868 T(n, n) = n!. - _G. C. Greubel_, Mar 07 2022 %e A158868 Triangle begins as: %e A158868 1; %e A158868 5, 2; %e A158868 14, 7, 6; %e A158868 126, 54, 54, 24; %e A158868 594, 297, 264, 132, 120; %e A158868 7722, 3432, 3432, 1560, 1560, 720; %e A158868 51480, 25740, 23400, 11700, 10800, 5400, 5040; %e A158868 875160, 397800, 397800, 183600, 183600, 85680, 85680, 40320; %e A158868 7558200, 3779100, 3488400, 1744200, 1627920, 813960, 766080, 383040, 362880; %t A158868 T[n_, k_]:= (2*n+1)!!*2^(1+Floor[n/2] +Floor[(k-1)/2])*Beta[Floor[n/2] +Floor[(k- 1)/2] +2, Floor[(n-1)/2] +Floor[k/2] +2]; %t A158868 Table[T[n, k], {n,10}, {k,n}]//Flatten (* modified by _G. C. Greubel_, Mar 07 2022 *) %o A158868 (Sage) %o A158868 def T(n,k): return (2*n+1).multifactorial(2)*2^(1+(n//2)+((k-1)//2))*beta(2+(n//2)+((k-1)//2), 2+((n-1)//2)+(k//2)) %o A158868 flatten([[T(n,k) for k in (1..n)] for n in (1..10)]) # _G. C. Greubel_, Mar 07 2022 %Y A158868 Cf. A158867. %K A158868 nonn,tabl %O A158868 1,2 %A A158868 _Roger L. Bagula_, Mar 28 2009 %E A158868 Edited by _G. C. Greubel_, Mar 07 2022