163863domain: NAppears in sequencesNumbers n such that determinant[{{n, sigma(n)}, {n+1, sigma(n+1)}}] is a perfect square.at n=5A067572Number of dispersed Dyck paths of length n (i.e., Motzkin paths of length n with no (1,0) steps at positive heights) with no valleys at level 0.at n=22A191388