One-half the number of permutations of length n with exactly 2 rising or falling successions.
A000349
One-half the number of permutations of length n with exactly 2 rising or falling successions.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =1a(4) =5a(5) =24a(6) =128a(7) =835a(8) =6423a(9) =56410a(10) =554306a(11) =6016077a(12) =71426225a(13) =920484892a(14) =12793635300a(15) =190730117959
External references
- oeis: A000349