Triangle read by rows: a(n,k) is the number of permutations of n elements with prefix transposition distance equal to k.
A164645
Triangle read by rows: a(n,k) is the number of permutations of n elements with prefix transposition distance equal to k.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =2a(6) =1a(7) =6a(8) =14a(9) =3a(10) =1a(11) =10a(12) =50a(13) =55a(14) =4a(15) =1a(16) =15a(17) =130a(18) =375a(19) =194a(20) =5a(21) =1a(22) =21a(23) =280a(24) =1575a(25) =2598a(26) =562a(27) =3a(28) =1a(29) =28
External references
- oeis: A164645