Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, down, up.
A177570
Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, down, up.
Terms
- a(0) =1a(1) =6a(2) =86a(3) =2147a(4) =86337a(5) =5048158a(6) =404763879a(7) =42661639277
External references
- oeis: A177570