a(n) = number of ways to dispose two pawns on a chessboard of size n X n (two dispositions are equivalent if one can be rotated or reflected to give the other one).
A141582
a(n) = number of ways to dispose two pawns on a chessboard of size n X n (two dispositions are equivalent if one can be rotated or reflected to give the other one).
Terms
- a(0) =0a(1) =0a(2) =2a(3) =8a(4) =21a(5) =48a(6) =93a(7) =168a(8) =278a(9) =440a(10) =660a(11) =960a(12) =1347a(13) =1848a(14) =2471a(15) =3248a(16) =4188a(17) =5328a(18) =6678a(19) =8280a(20) =10145a(21) =12320a(22) =14817a(23) =17688a(24) =20946a(25) =24648a(26) =28808a(27) =33488a(28) =38703a(29) =44520
External references
- oeis: A141582