5181491667domain: NAppears in sequencesNumber of lower triangles of an n X n integer array with all row and column sums zero and all row and column sums of squares <=18.at n=6A195887T(n,k) = Number of lower triangles of an n X n integer array with all row and column sums zero and all row and column sums of squares <= 2k^2.at n=42A195892