Number of permutations of {1,...,n} avoiding adjacent step pattern up, up, up, down, down, down.
A177552
Number of permutations of {1,...,n} avoiding adjacent step pattern up, up, up, down, down, down.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =720a(7) =5020a(8) =40000a(9) =358560a(10) =3571200a(11) =39124800a(12) =467596800a(13) =6054250840a(14) =84417778720
External references
- oeis: A177552