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 A176861 #10 Feb 08 2021 05:25:34 %S A176861 1,-6,-6,36,64,36,-240,-600,-600,-240,1800,5760,8100,5760,1800,-15120, %T A176861 -58800,-105840,-105840,-58800,-15120,141120,645120,1411200,1806336, %U A176861 1411200,645120,141120,-1451520,-7620480,-19595520,-30481920,-30481920,-19595520,-7620480,-1451520 %N A176861 Triangle T(n, k) = (-1)^n*(k+1)!*(n-k+1)!*binomial(n+2, k+2)*binomial(n+2, n-k+2) read by rows. %C A176861 Row sums are: 1, -12, 136, -1680, 23220, -359520, 6201216, -118298880, ... %D A176861 F. S. Roberts, Applied Combinatorics, Prentice-Hall, 1984, p. 576 and 270. %H A176861 G. C. Greubel, <a href="/A176861/b176861.txt">Rows n = 0..100 of the triangle, flattened</a> %F A176861 T(n, k) = (-1)^n*(k+1)!*(n-k+1)!*binomial(n+2, k+2)*binomial(n+2, n-k+2). %F A176861 T(n, k) = (-1)^n * A132159(n+2, k+2) * A132159(n+2, n-k+2). - _G. C. Greubel_, Feb 07 2021 %e A176861 Triangle begins as: %e A176861 1; %e A176861 -6, -6; %e A176861 36, 64, 36; %e A176861 -240, -600, -600, -240; %e A176861 1800, 5760, 8100, 5760, 1800; %e A176861 -15120, -58800, -105840, -105840, -58800, -15120; %e A176861 141120, 645120, 1411200, 1806336, 1411200, 645120, 141120; %t A176861 T[n_, k_]:= (-1)^n*(k+1)!*(n-k+1)!*Binomial[n+2, k+2]*Binomial[n+2, n-k+2]; %t A176861 Table[T[n, k], {n, 0, 12}, {k, 0, n}]//Flatten %o A176861 (Sage) flatten([[(-1)^n*factorial(k+1)*factorial(n-k+1)*binomial(n+2, k+2)*binomial(n+2, n-k+2) for k in (0..n)] for n in (0..12)]) # _G. C. Greubel_, Feb 07 2021 %o A176861 (Magma) [(-1)^n*Factorial(k+1)*Factorial(n-k+1)*Binomial(n+2, k+2)*Binomial(n+2, n-k+2): k in [0..n], n in [0..12]]; // _G. C. Greubel_, Feb 07 2021 %Y A176861 Cf. A132159. %K A176861 sign,tabl,easy,less %O A176861 0,2 %A A176861 _Roger L. Bagula_, Apr 27 2010 %E A176861 Edited by _G. C. Greubel_, Feb 07 2021