Number of permutations of [n] with exactly floor(n/2) rising or falling successions.
A322294
Number of permutations of [n] with exactly floor(n/2) rising or falling successions.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =48a(6) =120a(7) =888a(8) =2198a(9) =22120a(10) =54304a(11) =685368a(12) =1674468a(13) =25344480a(14) =61736880a(15) =1087931184a(16) =2644978110a(17) =53138966904a(18) =129019925424
External references
- oeis: A322294