Number of non-equivalent ways to place 2 non-attacking kings on an n X n board.

Terms

a(0) =0a(1) =0a(2) =4a(3) =13a(4) =37a(5) =75a(6) =147a(7) =246a(8) =406a(9) =610a(10) =910a(11) =1275a(12) =1779a(13) =2373a(14) =3157a(15) =4060a(16) =5212a(17) =6516a(18) =8136a(19) =9945a(20) =12145a(21) =14575a(22) =17479a(23) =20658a(24) =24402a(25) =28470a(26) =33202a(27) =38311a(28) =44191a(29) =50505