Triangle read by rows: T(n,k) is the number of even permutations (of an n-set) with exactly k fixed points.
A145224
Triangle read by rows: T(n,k) is the number of even permutations (of an n-set) with exactly k fixed points.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =0a(5) =1a(6) =2a(7) =0a(8) =0a(9) =1a(10) =3a(11) =8a(12) =0a(13) =0a(14) =1a(15) =24a(16) =15a(17) =20a(18) =0a(19) =0a(20) =1a(21) =130a(22) =144a(23) =45a(24) =40a(25) =0a(26) =0a(27) =1a(28) =930a(29) =910
External references
- oeis: A145224