Number of permutations of [n] with exactly floor(n/2) increasing runs of length two.
A317139
Number of permutations of [n] with exactly floor(n/2) increasing runs of length two.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =4a(4) =5a(5) =43a(6) =61a(7) =906a(8) =1385a(9) =31493a(10) =50521a(11) =1629248a(12) =2702765a(13) =117248463a(14) =199360981a(15) =11190963430a(16) =19391512145
External references
- oeis: A317139