979732224domain: NAppears in sequencesFrom least significant term in expansion of E( tr (X'*X)^n ), X rectangular and Gaussian. Also number of types of sequential n-swap moves for traveling salesman problem.at n=10A001171Triangle read by rows: T(n,k) (n >= 0, 1 <= k <= n+1) are the signed Hultman numbers.at n=55A189507