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 A209330 #22 Oct 16 2018 15:53:43 %S A209330 1,1,1,1,6,1,1,84,84,1,1,1820,12870,1820,1,1,53130,3268760,3268760, %T A209330 53130,1,1,1947792,1251677700,9075135300,1251677700,1947792,1,1, %U A209330 85900584,675248872536,39049918716424,39049918716424,675248872536,85900584,1,1 %N A209330 Triangle defined by T(n,k) = binomial(n^2, n*k), for n>=0, k=0..n, as read by rows. %C A209330 Column 1 equals A014062. %C A209330 Row sums equal A167009. %C A209330 Antidiagonal sums equal A209331. %C A209330 Ignoring initial row T(0,0), equals the logarithmic derivative of the g.f. of triangle A209196. %H A209330 Paul D. Hanna, <a href="/A209330/b209330.txt">Rows n = 0..30, as a flattened table of n, a(n) for n = 0..495</a> %e A209330 The triangle of coefficients C(n^2,n*k), n>=k, k=0..n, begins: %e A209330 1; %e A209330 1, 1; %e A209330 1, 6, 1; %e A209330 1, 84, 84, 1; %e A209330 1, 1820, 12870, 1820, 1; %e A209330 1, 53130, 3268760, 3268760, 53130, 1; %e A209330 1, 1947792, 1251677700, 9075135300, 1251677700, 1947792, 1; %e A209330 1, 85900584, 675248872536, 39049918716424, 39049918716424, 675248872536, 85900584, 1; ... %t A209330 Table[Binomial[n^2, n*k], {n,0,10}, {k,0,n}]//Flatten (* _G. C. Greubel_, Jan 05 2018 *) %o A209330 (PARI) {T(n,k)=binomial(n^2,n*k)} %o A209330 for(n=0,10,for(k=0,n,print1(T(n,k),", "));print("")) %Y A209330 Cf. A014062 (column 1), A167009 (row sums), A209331, A209196. %Y A209330 Cf. related triangles: A209196 (exp), A228836, A228832, A226234. %Y A209330 Cf. A206830. %K A209330 nonn,tabl %O A209330 0,5 %A A209330 _Paul D. Hanna_, Mar 06 2012