Number of ways to place 3 nonattacking wazirs on a 3 X n board.

Terms

a(0) =0a(1) =2a(2) =22a(3) =84a(4) =215a(5) =442a(6) =792a(7) =1292a(8) =1969a(9) =2850a(10) =3962a(11) =5332a(12) =6987a(13) =8954a(14) =11260a(15) =13932a(16) =16997a(17) =20482a(18) =24414a(19) =28820a(20) =33727a(21) =39162a(22) =45152a(23) =51724a(24) =58905a(25) =66722a(26) =75202a(27) =84372a(28) =94259a(29) =104890