255088domain: NAppears in sequencesNumber of cycles of length (2n+1)^2-1 on 2n+1 X 2n+1 square grid.at n=2A181584Number of longest cycles in the n X n grid graph.at n=6A301648Triangle read by rows: T(n,k) is the number of 2k-cycles in the n X n grid graph (2 <= k <= floor(n^2/2), n >= 2).at n=61A302337