221298739200domain: NAppears in sequencesa(n) = binomial(n,floor(n/2))*(n+1)!.at n=11A002867Number of n X n binary matrices with no 0 rows or columns and with n+1 1's.at n=11A055602Bishops on an 8n+1 X 8n+1 board (see Robinson paper for details).at n=6A123072a(n) = ((1+n)*floor(1+n/2))*(n!/floor(1+n/2)!)^2.at n=11A329965