Number of non-equivalent ways to place 5 non-attacking ferses on an n X n board.

Terms

a(0) =0a(1) =0a(2) =2a(3) =99a(4) =2102a(5) =19987a(6) =124676a(7) =571418a(8) =2122841a(9) =6704061a(10) =18711691a(11) =47235845a(12) =109938296a(13) =238950999a(14) =490309398a(15) =957267228a(16) =1790325363a(17) =3224010105a(18) =5615368229a(19) =9493358359a(20) =15627413290a(21) =25112609019a(22) =39484650296a(23) =60859027054a(24) =92114682749a(25) =137111560949a(26) =200972392655