Number of permutations of {1,...,n} avoiding adjacent step pattern up, up, down, up, down, down.
A177550
Number of permutations of {1,...,n} avoiding adjacent step pattern up, up, down, up, down, down.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =720a(7) =4950a(8) =38880a(9) =343440a(10) =3369600a(11) =36352800a(12) =427680000a(13) =5452027218a(14) =74846801304
External references
- oeis: A177550