Number of permutations of {1,...,n} avoiding adjacent step pattern up, down, down, up, up, down.
A177540
Number of permutations of {1,...,n} avoiding adjacent step pattern up, down, down, up, up, down.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =720a(7) =4908a(8) =38208a(9) =334368a(10) =3248640a(11) =34774112a(12) =405758208a(13) =5129918808a(14) =69849531936
External references
- oeis: A177540