Number of down-up permutations of n+5 starting with 5.
A006217
Number of down-up permutations of n+5 starting with 5.
Terms
- a(0) =5a(1) =16a(2) =56a(3) =224a(4) =1024a(5) =5296a(6) =30656a(7) =196544a(8) =1383424a(9) =10608976a(10) =88057856a(11) =786632864a(12) =7525556224a(13) =76768604656a(14) =831846342656
External references
- oeis: A006217