I will add these sequences to the OEIS: Queens: 0,0,0,2,21,131,733,3882,19641,97282... Kings: 0,0,1,7,46,240,1207,6004,28903,137996... Rooks: 0,0,1,9,48,242,1178,5793,27651,131383... Wazirs: 0,0,2,14,71,341,1591,7610,35432,165209... Best regards Neil