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 A176013 #10 Feb 08 2021 05:15:31
%S A176013 -1,2,1,-6,-9,-1,24,72,24,1,-120,-600,-400,-50,-1,720,5400,6000,1500,
%T A176013 90,1,-5040,-52920,-88200,-36750,-4410,-147,-1,40320,564480,1317120,
%U A176013 823200,164640,10976,224,1,-362880,-6531840,-20321280,-17781120,-5334336,-592704,-24192,-324,-1
%N A176013 Triangle, read by rows, T(n, k) = (-1)^n * n!/(k*k!) * binomial(n-1, k-1) * binomial(n, k-1).
%C A176013 Row sums are: -1, 3, -16, 121, -1171, 13711, -187468, 2920961, -50948677, 981458011, ...
%H A176013 G. C. Greubel, <a href="/A176013/b176013.txt">Rows n = 1..100 of the triangle, flattened</a>
%F A176013 T(n, k) = (-1)^n * n!/(k*k!) * binomial(n-1, k-1) * binomial(n, k-1).
%F A176013 T(n, k) = binomial(n+1, k) * A008297(n, k)/(n+1). - _G. C. Greubel_, Feb 08 2021
%e A176013 Triangle begins as:
%e A176013 -1;
%e A176013 2, 1;
%e A176013 -6, -9, -1;
%e A176013 24, 72, 24, 1;
%e A176013 -120, -600, -400, -50, -1;
%e A176013 720, 5400, 6000, 1500, 90, 1;
%e A176013 -5040, -52920, -88200, -36750, -4410, -147, -1;
%e A176013 40320, 564480, 1317120, 823200, 164640, 10976, 224, 1;
%e A176013 -362880, -6531840, -20321280, -17781120, -5334336, -592704, -24192, -324, -1;
%t A176013 T[n_, k_] = (-1)^n*n!/(k*k!)*Binomial[n-1, k-1]*Binomial[n, k-1];
%t A176013 Table[T[n, k], {n,12}, {k,n}]//Flatten
%o A176013 (Sage) flatten([[(-1)^n*(factorial(n)/(k*factorial(k)))*binomial(n-1, k-1)*binomial(n, k-1) for k in (1..n)] for n in (1..12)]) # _G. C. Greubel_, Feb 08 2021
%o A176013 (Magma) [(-1)^n*(Factorial(n)/(k*Factorial(k)))*Binomial(n-1, k-1)*Binomial(n, k-1) : k in [1..n], n in [1..12]]; // _G. C. Greubel_, Feb 08 2021
%Y A176013 Cf. A008297.
%K A176013 sign,tabl,easy,less
%O A176013 1,2
%A A176013 _Roger L. Bagula_, Apr 06 2010
%E A176013 Edited by _G. C. Greubel_, Feb 08 2021