Number of ways to place two nonattacking queens on an n X n board.

Terms

a(0) =0a(1) =0a(2) =8a(3) =44a(4) =140a(5) =340a(6) =700a(7) =1288a(8) =2184a(9) =3480a(10) =5280a(11) =7700a(12) =10868a(13) =14924a(14) =20020a(15) =26320a(16) =34000a(17) =43248a(18) =54264a(19) =67260a(20) =82460a(21) =100100a(22) =120428a(23) =143704a(24) =170200a(25) =200200a(26) =234000a(27) =271908a(28) =314244a(29) =361340