122092290831domain: NAppears in sequencesNumber of lower triangles of an n X n -3..3 array with all row and column sums zero.at n=6A195517T(n,k) = Number of lower triangles of an n X n -k..k array with all row and column sums zero.at n=42A195522Number of lower triangles of a 7X7 -n..n array with all row and column sums zero.at n=2A195525