821480domain: NAppears in sequencesRevert transform of (-1 + 3x^2)/(-1 - x + 4x^2 + x^3).at n=18A049132Triangle read by rows: T(n,k) is the number of self-avoiding paths of length 2*(n-1+k) connecting opposite corners in the n X n grid graph (0 <= k <= floor((n-1)^2/2), n >= 1).at n=37A333520