Number of inequivalent ways of placing 2 nonattacking rooks on n X n board up to rotations and reflections of the board.
A307304
Number of inequivalent ways of placing 2 nonattacking rooks on n X n board up to rotations and reflections of the board.
Terms
- a(0) =0a(1) =1a(2) =4a(3) =13a(4) =31a(5) =66a(6) =123a(7) =214a(8) =346a(9) =535a(10) =790a(11) =1131a(12) =1569a(13) =2128a(14) =2821a(15) =3676a(16) =4708a(17) =5949a(18) =7416a(19) =9145a(20) =11155a(21) =13486a(22) =16159a(23) =19218a(24) =22686a(25) =26611a(26) =31018a(27) =35959a(28) =41461a(29) =47580
External references
- oeis: A307304