Number of permutations of 0..(n-1) with the sum of the maximum of each adjacent pair = n*(n-1)/2 + floor((n-1)^2/8).
A180154
Number of permutations of 0..(n-1) with the sum of the maximum of each adjacent pair = n*(n-1)/2 + floor((n-1)^2/8).
Terms
- a(0) =2a(1) =4a(2) =8a(3) =36a(4) =160a(5) =848a(6) =5792a(7) =41712a(8) =338688a(9) =2902464a(10) =30968064a(11) =346316544a(12) =4034119680a(13) =48892557312a(14) =707976364032
External references
- oeis: A180154