cp's OEIS Frontend

A Brown's diagonal Latin square is a horizontally symmetric row-inverse (horizontal plane Brown's diagonal Latin square) or vertically symmetric column-inverse diagonal Latin square (vertical plane Brown's diagonal Latin square). Diagonal Latin squares of this type have interesting properties, for example, a large number of transversals.

Also number of vertical plane Brown's diagonal Latin squares of order 2n with the first row in order.

Plain symmetry diagonal Latin squares do not exist for odd orders.